and art of healing
. It encompasses a variety of health care
practices evolved to maintain and restore health
by the prevention and treatment
Contemporary medicine applies health science, biomedical research
, and medical technology
to diagnose and treat injury and disease, typically through medication or surgery
, but also through therapies as diverse as psychotherapy
, external splints & traction
, prostheses, biologics
, ionizing radiation and others.
"If you know neither the terminology nor the concepts, you're ignorant. If you know the terminology, but you don't know the concepts, you're dangerous."
"The unbiased opinion of most medical men of sound judgment and long experience...[holds that] the amount of death and disaster in the world would be less, if all disease were left to itself."
"Cured yesterday of my disease, I died last night of my physician."
"Our diseases are so old fashioned, they can't keep up with the new medicines."
"I firmly believe that if the whole material medica, as now used, could be sunk to the bottom of the sea, it would be better for mankind-and all the worse for the fishes."
"The college-birs are threeLaw, Physic and DivinityAnd while these three remain combined,They keep the world oppressed and blind...Now is the time to be set free,From priests' and Doctors' slavery.
"We should not encourage the medical student to while away his time in the labyrinths of Chemistry and Physiology."
"History is replete with examples of what happens when any group of authorities do not have to answer to empirical evidence but are free to define truth as they see fit. None of the examples has a happy ending. Why should it be otherwise with therapy?"
and art of healing
. It encompasses a variety of health care
practices evolved to maintain and restore health
by the prevention and treatment
Contemporary medicine applies health science, biomedical research
, and medical technology
to diagnose and treat injury and disease, typically through medication or surgery
, but also through therapies as diverse as psychotherapy
, external splints & traction
, prostheses, biologics
, ionizing radiation and others. The word medicine is derived from the Latin
ars medicina, meaning the art of healing.
incorporated plants (herbalism
), animal parts and minerals. In many cases these materials were used ritually as magical substances by priests, shamans, or medicine men
. Well-known spiritual systems include animism
(the notion of inanimate objects having spirits), spiritualism
(an appeal to gods or communion with ancestor spirits); shamanism
(the vesting of an individual with mystic powers); and divination
(magically obtaining the truth). The field of medical anthropology
examines the ways in which culture and society are organized around or impacted by issues of health, health care and related issues.
, Babylonian medicine, Ayurvedic
medicine (in the Indian subcontinent
), classical Chinese medicine (predecessor to the modern traditional Chinese Medicine
), and ancient Greek medicine and Roman medicine
. The Egyptian Imhotep
(3rd millennium BC) is the first physician in history known by name. Earliest records of dedicated hospitals come from Mihintale in Sri Lanka
where evidence of dedicated medicinal treatment facilities for patients are found. The Indian surgeon Sushruta described numerous surgical operations, including the earliest forms of plastic surgery
The Greek physician Hippocrates
, the "father of medicine", laid the foundation for a rational approach to medicine. Hippocrates introduced the Hippocratic Oath
for physicians, which is still relevant and in use today, and was the first to categorize illnesses as acute, chronic
and epidemic, and use terms such as, "exacerbation, relapse
, resolution, crisis, paroxysm, peak, and convalescence
The Greek physician Galen
was also one of the greatest surgeons of the ancient world and performed many audacious operations, including brain and eye surgeries. After the fall of the Western Roman Empire
and the onset of the Early Middle Ages
, the Greek tradition of medicine went into decline in Western Europe, although it continued uninterrupted in the Eastern Roman (Byzantine) Empire.
After 750 CE, the Muslim world had the works of Hippocrates, Galen and Sushruta translated into Arabic, and Islamic physicians
engaged in some significant medical research. Notable Islamic medical pioneers include the polymath
, who, along with Imhotep and Hippocrates, has also been called the "father of medicine". He wrote The Canon of Medicine
, considered one of the most famous books in the history of medicine. Others include Abulcasis, Avenzoar
, Ibn al-Nafis, and Averroes
. Rhazes was one of first to question the Greek theory of humorism
, which nevertheless remained influential in both medieval Western and medieval Islamic medicine
. The Islamic Bimaristan
hospitals were an early example of public hospital
However, the fourteenth and fifteenth century Black Death
was just as devastating to the Middle East as to Europe, and it has even been argued that Western Europe was generally more effective in recovering from the pandemic than the Middle East. In the early modern period, important early figures in medicine and anatomy emerged in Europe, including Gabriele Falloppio
and William Harvey
The major shift in medical thinking was the gradual rejection, especially during the Black Death
in the 14th and 15th centuries, of what may be called the 'traditional authority' approach to science and medicine. This was the notion that because some prominent person in the past said something must be so, then that was the way it was, and anything one observed to the contrary was an anomaly (which was paralleled by a similar shift in European society in general – see Copernicus
's rejection of Ptolemy
's theories on astronomy). Physicians like Vesalius
improved upon or disproved some of the theories from the past.
Andreas Vesalius was an author of one of the most influential books on human anatomy
, De humani corporis fabrica
. French surgeon Ambroise Paré
is considered as one of the fathers of surgery
. Bacteria and microorganisms were first observed with a microscope by Antonie van Leeuwenhoek in 1676, initiating the scientific field microbiology
. Partly based on the works by the Italian surgeon and anatomist Matteo Realdo Colombo the English physician William Harvey
described the circulatory system
. Herman Boerhaave
is sometimes referred to as a "father of physiology" due to his exemplary teaching in Leiden and textbook 'Institutiones medicae' (1708). It is said that the 17th century French physician Pierre Fauchard
science as we know it today, and he has been named "the father of modern dentistry".
Veterinary medicine was for the first time truly separated from human medicine in 1761, when the french veterinarian Claude Bourgelat founded the world's first veterinary school in Lyon, France. Before this, medical doctors treated both humans and animals.
Modern scientific biomedical research
(where results are testable and reproducible) began to replace early Western traditions based on herbalism, the Greek "four humours
" and other such pre-modern notions. The modern era really began with Edward Jenner
's discovery of the smallpox vaccine
at the end of the 18th century (inspired by the method of inoculation
earlier practiced in Asia), Robert Koch
's discoveries around 1880 of the transmission of disease by bacteria, and then the discovery of antibiotic
s around 1900.
The post-18th century modernity
period brought more groundbreaking researchers from Europe. From Germany
and Austria, doctors Rudolf Virchow
, Wilhelm Conrad Röntgen
, Karl Landsteiner
and Otto Loewi
made notable contributions. In the United Kingdom, Alexander Fleming
, Joseph Lister
, Francis Crick
and Florence Nightingale
are considered important. Spanish
doctor Santiago Ramón y Cajal
is considered the father of modern neuroscience
From New Zealand and Australia came Maurice Wilkins
, Howard Florey, and Frank Macfarlane Burnet
In the United States, William Williams Keen
, William Coley
, James D. Watson
, Italy (Salvador Luria), Switzerland (Alexandre Yersin
), Japan (Kitasato Shibasaburō
), and France (Jean-Martin Charcot
, Claude Bernard
, Paul Broca
and others did significant work). Russian Nikolai Korotkov
also did significant work, as did Sir William Osler
and Harvey Cushing
As science and technology developed, medicine became more reliant upon medication
s. Throughout history and in Europe right until the late 18th century, not only animal and plant products were used as medicine, but also human body parts and fluids. Pharmacology
developed from herbalism
and many drugs are still derived from plants (atropine, ephedrine, warfarin, aspirin
, digoxin, vinca alkaloids, taxol, hyoscine, etc.). Vaccine
s were discovered by Edward Jenner
and Louis Pasteur
The first antibiotic was arsphenamine
/ Salvarsan discovered by Paul Ehrlich
in 1908 after he observed that bacteria took up toxic dyes that human cells did not. The first major class of antibiotic
s was the sulfa
drugs, derived by French chemists originally from azo
Pharmacology has become increasingly sophisticated; modern biotechnology
allows drugs targeted towards specific physiological processes to be developed, sometimes designed for compatibility with the body to reduce side-effects
and knowledge of human genetics
is having some influence on medicine, as the causative gene
s of most monogenic genetic disorder
s have now been identified, and the development of techniques in molecular biology
and genetics are influencing medical technology, practice and decision-making.
is a contemporary movement to establish the most effective algorithms of practice (ways of doing things) through the use of systematic review
s and meta-analysis
. The movement is facilitated by modern global information science
, which allows as much of the available evidence as possible to be collected and analyzed according to standard protocols that are then disseminated to healthcare providers. The Cochrane Collaboration
leads this movement. A 2001 review of 160 Cochrane systematic reviews revealed that, according to two readers, 21.3% of the reviews concluded insufficient evidence, 20% concluded evidence of no effect, and 22.5% concluded positive effect.
Clinical practiceIn clinical practice, doctors personally assess patients in order to diagnose
, treat, and prevent disease using clinical judgment. The doctor-patient relationship
typically begins an interaction with an examination of the patient's medical history
and medical record
, followed a medical interview and a physical examination
. Basic diagnostic medical device
s (e.g. stethoscope
, tongue depressor
) are typically used. After examination for signs and interviewing for symptoms, the doctor may order medical test
s (e.g. blood test
s), take a biopsy
, or prescribe pharmaceutical drugs or other therapies. Differential diagnosis
methods help to rule out conditions based on the information provided. During the encounter, properly informing the patient of all relevant facts is an important part of the relationship and the development of trust. The medical encounter is then documented in the medical record, which is a legal document in many jurisdictions. Followups may be shorter but follow the same general procedure.
The components of the medical interview and encounter are:
- Chief complaint (cc): the reason for the current medical visit. These are the 'symptoms.' They are in the patient's own words and are recorded along with the duration of each one. Also called 'presenting complaint.'
- History of present illness / complaint (HPI): the chronological order of events of symptoms and further clarification of each symptom.
- Current activity: occupation, hobbies, what the patient actually does.
- MedicationMedicationA pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s (Rx): what drugs the patient takes including prescribed, over-the-counterOver-the-counter drugOver-the-counter drugs are medicines that may be sold directly to a consumer without a prescription from a healthcare professional, as compared to prescription drugs, which may be sold only to consumers possessing a valid prescription...
, and home remediesHome remedyA home remedy is a treatment to cure a disease or ailment that employs certain spices, vegetables, or other common items. Home remedies may or may not have medicinal properties that treat or cure the disease or ailment in question, as they are typically passed along by laypersons...
, as well as alternative and herbal medicines/herbal remediesHerbalismHerbalism is a traditional medicinal or folk medicine practice based on the use of plants and plant extracts. Herbalism is also known as botanical medicine, medical herbalism, herbal medicine, herbology, herblore, and phytotherapy...
. AllergiesAllergyAn Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...
are also recorded.
- Past medical history (PMH/PMHx): concurrent medical problems, past hospitalizations and operations, injuries, past infectious diseaseInfectious diseaseInfectious diseases, also known as communicable diseases, contagious diseases or transmissible diseases comprise clinically evident illness resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism...
s and/or vaccinationVaccinationVaccination is the administration of antigenic material to stimulate the immune system of an individual to develop adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens...
s, history of known allergies.
- Social history (SH): birthplace, residences, marital history, social and economic status, habits (including dietDiet (nutrition)In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
, medications, tobaccoTobacco smokingTobacco smoking is the practice where tobacco is burned and the resulting smoke is inhaled. The practice may have begun as early as 5000–3000 BCE. Tobacco was introduced to Eurasia in the late 16th century where it followed common trade routes...
- Family historyFamily history (medicine)In medicine, a family history consists of information about disorders from which the direct blood relatives of the patient have suffered. Genealogy typically includes very little of the medical history of the family, but the medical history could be considered a specific subset of the total history...
(FH): listing of diseases in the family that may impact the patient. A family treeFamily treeA family tree, or pedigree chart, is a chart representing family relationships in a conventional tree structure. The more detailed family trees used in medicine, genealogy, and social work are known as genograms.-Family tree representations:...
is sometimes used.
- Review of systems (ROS) or systems inquiry: a set of additional questions to ask, which may be missed on HPI: a general enquiry (have you noticed any weight lossWeight lossWeight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...
, change in sleep quality, fevers, lumps and bumps? etc.), followed by questions on the body's main organ systems (heartHuman heartThe human heart is a muscular organ that provides a continuous blood circulation through the cardiac cycle and is one of the most vital organs in the human body...
, lungHuman lungThe human lungs are the organs of respiration in humans. Humans have two lungs, with the left being divided into two lobes and the right into three lobes. Together, the lungs contain approximately of airways and 300 to 500 million alveoli, having a total surface area of about in...
s, digestive tractGastrointestinal tractThe human gastrointestinal tract refers to the stomach and intestine, and sometimes to all the structures from the mouth to the anus. ....
, urinary tractUrinary systemThe urinary system is the organ system that produces, stores, and eliminates urine. In humans it includes two kidneys, two ureters, the bladder and the urethra.-Kidney:...
The physical examination
is the examination of the patient looking for signs of disease ('Symptoms' are what the patient volunteers, 'Signs' are what the healthcare provider detects by examination). The healthcare provider uses the senses of sight, hearing, touch, and sometimes smell (e.g., in infection, uremia
, diabetic ketoacidosis
). Taste has been made redundant by the availability of modern lab tests. Four actions are taught as the basis of physical examination: inspection
(tap to determine resonance characteristics), and auscultation
(listen). This order may be modified depending on the main focus of the examination (e.g., a joint may be examined by simply "look, feel, move". Having this set order is an educational tool that encourages practitioners to be systematic in their approach and refrain from using tools such as the stethoscope
before they have fully evaluated the other modalities.
The clinical examination involves study of:
- Vital signs including height, weight, body temperature, blood pressureBlood pressureBlood pressure is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, BP varies...
, pulsePulseIn medicine, one's pulse represents the tactile arterial palpation of the heartbeat by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed against a bone, such as at the neck , at the wrist , behind the knee , on the inside of the elbow , and near the...
, respiration rate, hemoglobin oxygen saturationOxygen saturationOxygen saturation or dissolved oxygen is a relative measure of the amount of oxygen that is dissolved or carried in a given medium. It can be measured with a dissolved oxygen probe such as an oxygen sensor or an optode in liquid media, usually water.It has particular significance in medicine and...
- General appearance of the patient and specific indicators of disease (nutritional status, presence of jaundice, pallor or clubbing)
- SkinHuman skinThe human skin is the outer covering of the body. In humans, it is the largest organ of the integumentary system. The skin has multiple layers of ectodermal tissue and guards the underlying muscles, bones, ligaments and internal organs. Human skin is similar to that of most other mammals,...
- Head, eye, earEarThe ear is the organ that detects sound. It not only receives sound, but also aids in balance and body position. The ear is part of the auditory system....
, nose, and throat (HEENT)
- Cardiovascular (heartHeartThe heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
and blood vesselBlood vesselThe blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
- Respiratory (large airways and lungs)
- AbdomenAbdomenIn vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
and rectumRectumThe rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
- Genitalia (and pregnancy if the patient is or could be pregnant)
- Musculoskeletal (including spine and extremities)
- Neurological (consciousness, awareness, brain, vision, cranial nervesCranial nervesCranial nerves are nerves that emerge directly from the brain, in contrast to spinal nerves, which emerge from segments of the spinal cord. In humans, there are traditionally twelve pairs of cranial nerves...
, spinal cord and peripheral nervesPeripheral nervous systemThe peripheral nervous system consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system to the limbs and organs. Unlike the CNS, the PNS is not protected by the bone of spine and skull, or by the blood–brain...
- Psychiatric (orientation, mental state, evidence of abnormal perception or thought).
It is to likely focus on areas of interest highlighted in the medical history and may not include everything listed above.
and imaging studies
results may be obtained, if necessary.
The medical decision-making (MDM) process involves analysis and synthesis of all the above data to come up with a list of possible diagnoses (the differential diagnoses
), along with an idea of what needs to be done to obtain a definitive diagnosis that would explain the patient's problem.
The treatment plan may include ordering additional laboratory tests and studies, starting therapy, referral to a specialist, or watchful observation. Follow-up may be advised.
This process is used by primary care providers as well as specialists. It may take only a few minutes if the problem is simple and straightforward. On the other hand, it may take weeks in a patient who has been hospitalized with bizarre symptoms or multi-system problems, with involvement by several specialists.
On subsequent visits, the process may be repeated in an abbreviated manner to obtain any new history, symptoms, physical findings, and lab or imaging results or specialist consultations.
InstitutionsContemporary medicine is in general conducted within health care system
s. Legal, credential
ing and financing frameworks are established by individual governments, augmented on occasion by international organizations. The characteristics of any given health care system have significant impact on the way medical care is provided.
Advanced industrial countries (with the exception of the United States) and many developing countries
provide medical services through a system of universal health care
that aims to guarantee care for all through a single-payer health care
system, or compulsory private or co-operative health insurance
. This is intended to ensure that the entire population has access to medical care on the basis of need rather than ability to pay. Delivery may be via private medical practices or by state-owned hospitals and clinics, or by charities, most commonly by a combination of all three.
societies, but also some capitalist countries and the United States, provide no guarantee of healthcare for the population as a whole. In such societies, healthcare is available to those that can afford to pay for it or have self-insured it (either directly or as part of an employment contract) or who may be covered by care financed by the government or tribe directly.
DeliveryProvision of medical care is classified into primary, secondary, and tertiary care categories.
medical services are provided by physicians, physician assistants, nurse practitioners, or other health professionals who have first contact with a patient seeking medical treatment or care. These occur in physician offices, clinic
s, nursing home
s, schools, home visits, and other places close to patients. About 90% of medical visits can be treated by the primary care provider. These include treatment of acute and chronic illnesses, preventive care and health education
for all ages and both sexes.
Secondary care medical services are provided by medical specialists in their offices or clinics or at local community hospitals for a patient referred by a primary care provider who first diagnosed or treated the patient. Referrals are made for those patients who required the expertise or procedures performed by specialists. These include both ambulatory care
and inpatient services, emergency room
s, intensive care medicine
, surgery services, physical therapy
, labor and delivery
units, diagnostic laboratory
and medical imaging
services, hospice centers, etc. Some primary care providers may also take care of hospitalized patients and deliver babies in a secondary care setting.
Tertiary care medical services are provided by specialist hospitals or regional centers equipped with diagnostic and treatment facilities not generally available at local hospitals. These include trauma center
treatment centers, advanced neonatology
unit services, organ transplant
s, high-risk pregnancy, radiation
Modern medical care also depends on information – still delivered in many health care settings on paper records, but increasingly nowadays by electronic means.
BranchesWorking together as an interdisciplinary team, many highly trained health profession
als besides medical practitioners are involved in the delivery of modern health care. Examples include: nurses, emergency medical technician
s and paramedics, laboratory scientists, pharmacists, physiotherapists, respiratory therapists, speech therapists, occupational therapists
, radiographers, dietitian
s, and bioengineers.
The scope and sciences underpinning human medicine overlap many other fields. Dentistry
, while a separate discipline from medicine, is considered a medical field.
A patient admitted to hospital is usually under the care of a specific team based on their main presenting problem, e.g., the Cardiology team, who then may interact with other specialties, e.g., surgical, radiology, to help diagnose or treat the main problem or any subsequent complications/developments.
Physicians have many specializations and subspecializations into certain branches of medicine, which are listed below. There are variations from country to country regarding which specialties certain subspecialties are in.
The main branches of medicine are:
- Basic sciences of medicine; this is what every physician is educated in, and some return to in biomedical research.
- Medical specialties
- Interdisciplinary fields, where different medical specialties are mixed to function in certain occasions.
- AnatomyAnatomyAnatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
is the study of the physical structure of organismOrganismIn biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
s. In contrast to macroscopic or gross anatomy, cytology and histology are concerned with microscopic structures.
- BiochemistryBiochemistryBiochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
is the study of the chemistry taking place in living organisms, especially the structure and function of their chemical components.
- BiomechanicsBiomechanicsBiomechanics is the application of mechanical principles to biological systems, such as humans, animals, plants, organs, and cells. Perhaps one of the best definitions was provided by Herbert Hatze in 1974: "Biomechanics is the study of the structure and function of biological systems by means of...
is the study of the structure and function of biological systems by means of the methods of MechanicsMechanicsMechanics is the branch of physics concerned with the behavior of physical bodies when subjected to forces or displacements, and the subsequent effects of the bodies on their environment....
- BiostatisticsBiostatisticsBiostatistics is the application of statistics to a wide range of topics in biology...
is the application of statistics to biological fields in the broadest sense. A knowledge of biostatistics is essential in the planning, evaluation, and interpretation of medical research. It is also fundamental to epidemiologyEpidemiologyEpidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
and evidence-based medicine.
- BiophysicsBiophysicsBiophysics is an interdisciplinary science that uses the methods of physical science to study biological systems. Studies included under the branches of biophysics span all levels of biological organization, from the molecular scale to whole organisms and ecosystems...
is an interdisciplinary science that uses the methods of physicsPhysicsPhysics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
and physical chemistryPhysical chemistryPhysical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts...
to study biological systems.
- CytologyCell biologyCell biology is a scientific discipline that studies cells – their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death. This is done both on a microscopic and molecular level...
is the microscopic study of individual cellsCell (biology)The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
- EmbryologyEmbryologyEmbryology is a science which is about the development of an embryo from the fertilization of the ovum to the fetus stage...
is the study of the early development of organisms.
- EndocrinologyEndocrinologyEndocrinology is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions called hormones, the integration of developmental events such as proliferation, growth, and differentiation and the coordination of...
is the study of hormones and their effect throughout the body of animals.
- EpidemiologyEpidemiologyEpidemiology is the study of health-event, health-characteristic, or health-determinant patterns in a population. It is the cornerstone method of public health research, and helps inform policy decisions and evidence-based medicine by identifying risk factors for disease and targets for preventive...
is the study of the demographics of disease processes, and includes, but is not limited to, the study of epidemics.
- GeneticsGeneticsGenetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
is the study of genes, and their role in biological inheritance.
- HistologyHistologyHistology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...
is the study of the structures of biological tissueBiological tissueTissue is a cellular organizational level intermediate between cells and a complete organism. A tissue is an ensemble of cells, not necessarily identical, but from the same origin, that together carry out a specific function. These are called tissues because of their identical functioning...
s by light microscopyMicroscopyMicroscopy is the technical field of using microscopes to view samples and objects that cannot be seen with the unaided eye...
, electron microscopyElectron microscopeAn electron microscope is a type of microscope that uses a beam of electrons to illuminate the specimen and produce a magnified image. Electron microscopes have a greater resolving power than a light-powered optical microscope, because electrons have wavelengths about 100,000 times shorter than...
and immunohistochemistryImmunohistochemistryImmunohistochemistry or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...
- ImmunologyImmunologyImmunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. It deals with the physiological functioning of the immune system in states of both health and diseases; malfunctions of the immune system in immunological disorders ; the...
is the study of the immune systemImmune systemAn immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
, which includes the innate and adaptive immune system in humans, for example.
- Medical physicsMedical physicsMedical physics is the application of physics to medicine. It generally concerns physics as applied to medical imaging and radiotherapy, although a medical physicist may also work in many other areas of healthcare...
is the study of the applications of physics principles in medicine.
- MicrobiologyMicrobiologyMicrobiology is the study of microorganisms, which are defined as any microscopic organism that comprises either a single cell , cell clusters or no cell at all . This includes eukaryotes, such as fungi and protists, and prokaryotes...
is the study of microorganismMicroorganismA microorganism or microbe is a microscopic organism that comprises either a single cell , cell clusters, or no cell at all...
s, including protozoaProtozoaProtozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...
, bacteria, fungiFungusA fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
, and virusVirusA virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
- Molecular biologyMolecular biologyMolecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
is the study of molecular underpinnings of the process of replicationReplicationReplication may refer to:Science* Replication is one of the main principles of the scientific method, a.k.a. reproducibility** Replication , the repetition of a test or complete experiment...
, transcriptionTranscription (genetics)Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...
and translationTranslationTranslation is the communication of the meaning of a source-language text by means of an equivalent target-language text. Whereas interpreting undoubtedly antedates writing, translation began only after the appearance of written literature; there exist partial translations of the Sumerian Epic of...
of the genetic material.
- NeuroscienceNeuroscienceNeuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
includes those disciplines of science that are related to the study of the nervous systemNervous systemThe nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
. A main focus of neuroscience is the biologyBiologyBiology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
and physiology of the human brain and spinal cordSpinal cordThe spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain . The brain and spinal cord together make up the central nervous system...
. Some related clinical specialties include neurologyNeurologyNeurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
, neurosurgeryNeurosurgeryNeurosurgery is the medical specialty concerned with the prevention, diagnosis, treatment, and rehabilitation of disorders which affect any portion of the nervous system including the brain, spine, spinal cord, peripheral nerves, and extra-cranial cerebrovascular system.-In the United States:In...
and psychiatryPsychiatryPsychiatry is the medical specialty devoted to the study and treatment of mental disorders. These mental disorders include various affective, behavioural, cognitive and perceptual abnormalities...
- Nutrition science (theoretical focus) and dietetics (practical focus) is the study of the relationship of food and drink to health and disease, especially in determining an optimal diet. Medical nutrition therapy is done by dietitians and is prescribed for diabetes, cardiovascular diseaseCardiovascular diseaseHeart disease or cardiovascular disease are the class of diseases that involve the heart or blood vessels . While the term technically refers to any disease that affects the cardiovascular system , it is usually used to refer to those related to atherosclerosis...
s, weight and eating disorderMental illnessA mental disorder or mental illness is a psychological or behavioral pattern generally associated with subjective distress or disability that occurs in an individual, and which is not a part of normal development or culture. Such a disorder may consist of a combination of affective, behavioural,...
s, allergies, malnutritionMalnutritionMalnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....
, and neoplasticNeoplasiaNeoplasm is an abnormal mass of tissue as a result of neoplasia. Neoplasia is the abnormal proliferation of cells. The growth of neoplastic cells exceeds and is not coordinated with that of the normal tissues around it. The growth persists in the same excessive manner even after cessation of the...
- Pathology as a science is the study of disease—the causes, course, progression and resolution thereof.
- PharmacologyPharmacologyPharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...
is the study of drugs and their actions.
- PhotobiologyPhotobiologyPhotobiology is the scientific study of the interactions of light and living organisms. The field includes the study of photosynthesis, photomorphogenesis, visual processing, circadian rhythms, bioluminescence, and ultraviolet radiation effects...
is the study of the interactions between non-ionizing radiationNon-ionizing radiationNon-ionizing radiation refers to any type of electromagnetic radiation that does not carry enough energy per quantum to ionize atoms or molecules—that is, to completely remove an electron from an atom or molecule...
and living organisms.
- PhysiologyPhysiologyPhysiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
is the study of the normal functioning of the body and the underlying regulatory mechanisms.
- RadiobiologyRadiobiologyRadiobiology , as a field of clinical and basic medical sciences, originated from Leopold Freund's 1896 demonstration of the therapeutic treatment of a hairy mole using a new type of electromagnetic radiation called x-rays, which was discovered 1 year previously by the German physicist, Wilhelm...
is the study of the interactions between ionizing radiationIonizing radiationIonizing radiation is radiation composed of particles that individually have sufficient energy to remove an electron from an atom or molecule. This ionization produces free radicals, which are atoms or molecules containing unpaired electrons...
and living organisms.
- ToxicologyToxicologyToxicology is a branch of biology, chemistry, and medicine concerned with the study of the adverse effects of chemicals on living organisms...
is the study of hazardous effects of drugs and poisonPoisonIn the context of biology, poisons are substances that can cause disturbances to organisms, usually by chemical reaction or other activity on the molecular scale, when a sufficient quantity is absorbed by an organism....
SpecialtiesIn the broadest meaning of "medicine", there are many different specialties. In the UK, most specialities will have their own body or college (collectively known as the Royal Colleges, although currently not all use the term "Royal"), which have their own entrance exam. The development of a speciality is often driven by new technology (such as the development of effective anaesthetics) or ways of working (e.g., emergency departments), which leads to the desire to form a unifying body of doctors and thence the prestige of administering their own exam.
Within medical circles, specialities usually fit into one of two broad categories: "Medicine" and "Surgery." "Medicine" refers to the practice of non-operative medicine, and most subspecialties in this area require preliminary training in "Internal Medicine". In the UK, this would traditionally have been evidenced by obtaining the MRCP (An exam allowing Membership of the Royal College of Physicians
or the equivalent college in Scotland or Ireland). "Surgery" refers to the practice of operative medicine, and most subspecialties in this area require preliminary training in "General Surgery." (In the UK: Membership of the Royal College of Surgeons of England
(MRCS).)There are some specialties of medicine that at the present time do not fit easily into either of these categories, such as radiology, pathology, or anesthesia. Most of these have branched from one or other of the two camps above – for example anaesthesia developed first as a faculty of the Royal College of Surgeons (for which MRCS/FRCS would have been required) before becoming the Royal College of Anaesthetists
and membership of the college is by sitting the FRCA (Fellowship of the Royal College of Anesthetists).
SurgerySurgical specialties employ operative treatment. In addition, surgeons must decide when an operation is necessary, and also treat many non-surgical issues, particularly in the surgical intensive care unit (SICU), where a variety of critical issues arise. Surgeons must also manage pre-operative, post-operative, and potential surgical candidates on the hospital wards. Surgery has many sub-specialties, including general surgery
, cardiovascular surgery, colorectal surgery, neurosurgery
, maxillofacial surgery, orthopedic surgery
, plastic surgery
, oncologic surgery, transplant surgery, trauma surgery
, vascular surgery
, and pediatric surgery
. In some centers, anesthesiology is part of the division of surgery (for historical and logistical reasons), although it is not a surgical discipline. Other medical specialties may employ surgical procedures, such as ophthalmology
, but are not considered surgical sub-specialties per se.
Surgical training in the U.S. requires a minimum of five years of residency after medical school. Sub-specialties of surgery often require seven or more years. In addition, fellowships can last an additional one to three years. Because post-residency fellowships can be competitive, many trainees devote two additional years to research. Thus in some cases surgical training will not finish until more than a decade after medical school. Furthermore, surgical training can be very difficult and time consuming.
'Medicine' as a specialtyInternal medicine is the medical specialty
concerned with the diagnosis, management and nonsurgical treatment of unusual or serious diseases, either of one particular organ system or of the body as a whole. According to some sources, an emphasis on internal structures is implied. In North America, specialists in internal medicine are commonly called "internists". Elsewhere, especially in Commonwealth
nations, such specialists are often called physician
s. These terms, internist or physician (in the narrow sense, common outside North America), generally exclude practitioners of gynecology and obstetrics, pathology, psychiatry, and especially surgery and its subspecialities.
Because their patients are often seriously ill or require complex investigations, internists do much of their work in hospitals. Formerly, many internists were not subspecialized; such general physicians would see any complex nonsurgical problem; this style of practice has become much less common. In modern urban practice, most internists are subspecialists: that is, they generally limit their medical practice to problems of one organ system or to one particular area of medical knowledge. For example, gastroenterologist
s and nephrologist
s specialize respectively in diseases of the gut and the kidneys.
In the Commonwealth of Nations
and some other countries, specialist pediatricians
are also described as specialist physicians (or internists) who have subspecialized by age of patient rather than by organ system. Elsewhere, especially in North America, general pediatrics is often a form of Primary care
There are many subspecialities (or subdisciplines) of internal medicine
Training in internal medicine (as opposed to surgical training), varies considerably across the world: see the articles on Medical education
for more details. In North America, it requires at least three years of residency training after medical school, which can then be followed by a one to three year fellowship in the subspecialties listed above. In general, resident work hours in medicine are less than those in surgery, averaging about 60 hours per week in the USA. This difference does not apply in the UK where all doctors are now required by law to work less than 48 hours per week on average.
- Clinical laboratory sciences are the clinical diagnostic services that apply laboratory techniques to diagnosis and management of patients. In the United States, these services are supervised by a pathologist. The personnel that work in these medical laboratoryMedical laboratoryA medical laboratory or clinical laboratory is a laboratory where tests are done on clinical specimens in order to get information about the health of a patient as pertaining to the diagnosis, treatment, and prevention of disease.-Departments:...
departments are technically trained staff who do not hold medical degrees, but who usually hold an undergraduate medical technologyMedical technologyMedical Technology encompasses a wide range of healthcare products and is used to diagnose, monitor or treat diseases or medical conditions affecting humans. Such technologies are intended to improve the quality of healthcare delivered through earlier diagnosis, less invasive treatment options and...
degree, who actually perform the testMedical testA diagnostic test is any kind of medical test performed to aid in the diagnosis or detection of disease. For example:* to diagnose diseases, and preferably sub-classify it regarding, for example, severity and treatability...
s, assayAssayAn assay is a procedure in molecular biology for testing or measuring the activity of a drug or biochemical in an organism or organic sample. A quantitative assay may also measure the amount of a substance in a sample. Bioassays and immunoassays are among the many varieties of specialized...
s, and procedures needed for providing the specific services. Subspecialties include Transfusion medicineTransfusion medicineTransfusion medicine is the branch of medicine that is concerned with the transfusion of blood and blood components. The blood bank is the section of the clinical laboratory where medical technologists process and distribute blood products under the supervision of a medical director, often...
, Cellular pathology, Clinical chemistry, HematologyHematologyHematology, also spelled haematology , is the branch of biology physiology, internal medicine, pathology, clinical laboratory work, and pediatrics that is concerned with the study of blood, the blood-forming organs, and blood diseases...
, Clinical microbiology and Clinical immunology.
- Pathology as a medical specialtyPathology as a medical specialtyPathologists are physicians who diagnose and characterize disease in living patients by examining biopsies or bodily fluid. Pathologists may also conduct autopsies to investigate causes of death. Pathology is a core discipline of medical school and many pathologists are also instructors...
is the branch of medicine that deals with the study of diseases and the morphologic, physiologic changes produced by them. As a diagnostic specialty, pathology can be considered the basis of modern scientific medical knowledge and plays a large role in evidence-based medicineEvidence-based medicineEvidence-based medicine or evidence-based practice aims to apply the best available evidence gained from the scientific method to clinical decision making. It seeks to assess the strength of evidence of the risks and benefits of treatments and diagnostic tests...
. Many modern molecular tests such as flow cytometryFlow cytometryFlow cytometry is a technique for counting and examining microscopic particles, such as cells and chromosomes, by suspending them in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and/or chemical...
, polymerase chain reactionPolymerase chain reactionThe polymerase chain reaction is a scientific technique in molecular biology to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence....
(PCR), immunohistochemistryImmunohistochemistryImmunohistochemistry or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...
, cytogeneticsCytogeneticsCytogenetics is a branch of genetics that is concerned with the study of the structure and function of the cell, especially the chromosomes. It includes routine analysis of G-Banded chromosomes, other cytogenetic banding techniques, as well as molecular cytogenetics such as fluorescent in situ...
, gene rearrangements studies and fluorescent in situ hybridizationFluorescent in situ hybridizationFISH is a cytogenetic technique developed by biomedical researchers in the early 1980s that is used to detect and localize the presence or absence of specific DNA sequences on chromosomes. FISH uses fluorescent probes that bind to only those parts of the chromosome with which they show a high...
(FISH) fall within the territory of pathology.
- RadiologyRadiologyRadiology is a medical specialty that employs the use of imaging to both diagnose and treat disease visualized within the human body. Radiologists use an array of imaging technologies to diagnose or treat diseases...
is concerned with imaging of the human body, e.g. by x-rayX-rayX-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s, x-ray computed tomographyComputed tomographyX-ray computed tomography or Computer tomography , is a medical imaging method employing tomography created by computer processing...
, ultrasonography, and nuclear magnetic resonanceNuclear magnetic resonanceNuclear magnetic resonance is a physical phenomenon in which magnetic nuclei in a magnetic field absorb and re-emit electromagnetic radiation...
tomographyTomographyTomography refers to imaging by sections or sectioning, through the use of any kind of penetrating wave. A device used in tomography is called a tomograph, while the image produced is a tomogram. The method is used in radiology, archaeology, biology, geophysics, oceanography, materials science,...
- Nuclear medicineNuclear medicineIn nuclear medicine procedures, elemental radionuclides are combined with other elements to form chemical compounds, or else combined with existing pharmaceutical compounds, to form radiopharmaceuticals. These radiopharmaceuticals, once administered to the patient, can localize to specific organs...
is concerned with studying human organ systems by administering radiolabelled substances (radiopharmaceuticals) to the body, which can then be imaged outside the body by a gamma cameraGamma cameraA gamma camera, also called a scintillation camera or Anger camera, is a device used to image gamma radiation emitting radioisotopes, a technique known as scintigraphy...
or a PET scanner. Each radiopharmaceutical consists of two parts: a tracer that is specific for the function under study (e.g., neurotransmitter pathway, metabolic pathway, blood flow, or other), and a radionuclide (usually either a gamma-emitter or a positron emitter). There is a degree of overlap between nuclear medicine and radiology, as evidenced by the emergence of combined devices such as the PET/CT scanner.
- Clinical neurophysiologyClinical neurophysiologyClinical neurophysiology is a medical specialty that studies the central and peripheral nervous systems through the recording of bioelectrical activity, whether spontaneous or stimulated....
is concerned with testing the physiology or function of the central and peripheral aspects of the nervous system. These kinds of tests can be divided into recordings of: (1) spontaneous or continuously running electrical activity, or (2) stimulus evoked responses. Subspecialties include ElectroencephalographyElectroencephalographyElectroencephalography is the recording of electrical activity along the scalp. EEG measures voltage fluctuations resulting from ionic current flows within the neurons of the brain...
, ElectromyographyElectromyographyElectromyography is a technique for evaluating and recording the electrical activity produced by skeletal muscles. EMG is performed using an instrument called an electromyograph, to produce a record called an electromyogram. An electromyograph detects the electrical potential generated by muscle...
, Evoked potentialEvoked potentialAn evoked potential is an electrical potential recorded from the nervous system of a human or other animal following presentation of a stimulus, as distinct from spontaneous potentials as detected by electroencephalography or electromyography .Evoked potential amplitudes tend to be low, ranging...
, Nerve conduction studyNerve conduction studyA nerve conduction study is a test commonly used to evaluate the function, especially the ability of electrical conduction, of the motor and sensory nerves of the human body.Nerve conduction velocity is a common measurement made during this test...
and PolysomnographyPolysomnographyPolysomnography , also known as a sleep study, is a multi-parametric test used in the study of sleep and as a diagnostic tool in sleep medicine. The test result is called a polysomnogram, also abbreviated PSG...
. Sometimes these tests are performed by techs without a medical degree, but the interpretation of these tests is done by a medical professional.
Other major specialtiesThe followings are some major medical specialties that do not directly fit into any of the above mentioned groups.
- Anesthesiology (also known as anaesthetics): concerned with the perioperative management of the surgical patient. The anesthesiologist's role during surgery is to prevent derangement in the vital organs' (i.e. brain, heart, kidneys) functions and postoperative pain. Outside of the operating room, the anesthesiology physician also served the same function in the labor & delivery ward, and some are specialized in critical medicine.
- DermatologyDermatologyDermatology is the branch of medicine dealing with the skin and its diseases, a unique specialty with both medical and surgical aspects. A dermatologist takes care of diseases, in the widest sense, and some cosmetic problems of the skin, scalp, hair, and nails....
is concerned with the skin and its diseases. In the UK, dermatology is a subspecialty of general medicine.
- Emergency medicineEmergency medicineEmergency medicine is a medical specialty in which physicians care for patients with acute illnesses or injuries which require immediate medical attention. While not usually providing long-term or continuing care, emergency medicine physicians diagnose a variety of illnesses and undertake acute...
is concerned with the diagnosis and treatment of acute or life-threatening conditions, including traumaPhysical traumaTrauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
, surgical, medical, pediatric, and psychiatric emergencies.
- Family medicineFamily medicineFamily medicine is a medical specialty devoted to comprehensive health care for people of all ages. It is a division of primary care that provides continuing and comprehensive health care for the individual and family across all ages, sexes, diseases, and parts of the body...
, family practice, general practice or primary care is, in many countries, the first port-of-call for patients with non-emergency medical problems. Family physicians often provide services across a broad range of settings including office based practices, emergency room coverage, inpatient care, and nursing home care.
- ObstetricsObstetricsObstetrics is the medical specialty dealing with the care of all women's reproductive tracts and their children during pregnancy , childbirth and the postnatal period...
and gynecology (often abbreviated as OB/GYN (American English) or Obs & Gynae (British English)) are concerned respectively with childbirth and the female reproductive and associated organs. Reproductive medicineReproductive medicineReproductive medicine is a branch of medicine that deals with prevention, diagnosis and management of reproductive problems; goals include improving or maintaining reproductive health and allowing people to have children at a time of their choosing...
and fertility medicine are generally practiced by gynecological specialists.
- Medical GeneticsMedical geneticsMedical genetics is the specialty of medicine that involves the diagnosis and management of hereditary disorders. Medical genetics differs from Human genetics in that human genetics is a field of scientific research that may or may not apply to medicine, but medical genetics refers to the...
is concerned with the diagnosis and management of hereditary disorders.
- NeurologyNeurologyNeurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
is concerned with diseases of the nervous system. In the UK, neurology is a subspecialty of general medicine.
- OphthalmologyOphthalmologyOphthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eye. An ophthalmologist is a specialist in medical and surgical eye problems...
exclusively concerned with the eye and ocular adnexa, combining conservative and surgical therapy.
- PediatricsPediatricsPediatrics or paediatrics is the branch of medicine that deals with the medical care of infants, children, and adolescents. A medical practitioner who specializes in this area is known as a pediatrician or paediatrician...
(AE) or paediatrics (BE) is devoted to the care of infants, children, and adolescents. Like internal medicine, there are many pediatric subspecialties for specific age ranges, organ systems, disease classes, and sites of care delivery.
- Physical medicine and rehabilitationPhysical medicine and rehabilitationPhysical medicine and rehabilitation , physiatry or rehabilitation medicine, is a branch of medicine that aims to enhance and restore functional ability and quality of life to those with physical impairments or disabilities. A physician having completed training in this field is referred to as a...
(or physiatry) is concerned with functional improvement after injury, illness, or congenital disorderCongenital disorderA congenital disorder, or congenital disease, is a condition existing at birth and often before birth, or that develops during the first month of life , regardless of causation...
- PsychiatryPsychiatryPsychiatry is the medical specialty devoted to the study and treatment of mental disorders. These mental disorders include various affective, behavioural, cognitive and perceptual abnormalities...
is the branch of medicine concerned with the bio-psycho-social study of the etiologyEtiologyEtiology is the study of causation, or origination. The word is derived from the Greek , aitiologia, "giving a reason for" ....
, diagnosis, treatment and prevention of cognitive, perceptual, emotional and behavioral disorders. Related non-medical fields include psychotherapyPsychotherapyPsychotherapy is a general term referring to any form of therapeutic interaction or treatment contracted between a trained professional and a client or patient; family, couple or group...
and clinical psychologyClinical psychologyClinical psychology is an integration of science, theory and clinical knowledge for the purpose of understanding, preventing, and relieving psychologically-based distress or dysfunction and to promote subjective well-being and personal development...
- Preventive medicinePreventive medicinePreventive medicine or preventive care refers to measures taken to prevent diseases, rather than curing them or treating their symptoms...
is the branch of medicine concerned with preventing disease.
- Community healthCommunity healthCommunity health, a field of public health, is a discipline that concerns itself with the study and betterment of the health characteristics of biological communities. While the term community can be broadly defined, community health tends to focus on geographic areas rather than people with shared...
or public healthPublic healthPublic health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...
is an aspect of health services concerned with threats to the overall health of a community based on population healthPopulation healthPopulation health has been defined as “the health outcomes of a group of individuals, including the distribution of such outcomes within the group.” It is an approach to health that aims to improve the health of an entire population. One major step in achieving this aim is to reduce health...
- Occupational medicines principal role is the provision of health advice to organizations and individuals to ensure that the highest standards of health and safety at work can be achieved and maintained.
- Aerospace medicine deals with medical problems related to flying and space travelHuman spaceflightHuman spaceflight is spaceflight with humans on the spacecraft. When a spacecraft is manned, it can be piloted directly, as opposed to machine or robotic space probes and remotely-controlled satellites....
- Community health
Some interdisciplinary sub-specialties of medicine include:
- Addiction medicineAddiction MedicineAddiction medicine is a medical specialty that deals with the treatment of addiction. The specialty often crosses over into other areas, since various aspects of addiction fall within the fields of public health, psychology, social work, psychiatry, and internal medicine, among others...
deals with the treatment of addiction.
- Medical ethicsMedical ethicsMedical ethics is a system of moral principles that apply values and judgments to the practice of medicine. As a scholarly discipline, medical ethics encompasses its practical application in clinical settings as well as work on its history, philosophy, theology, and sociology.-History:Historically,...
deals with ethical and moralMoralA moral is a message conveyed or a lesson to be learned from a story or event. The moral may be left to the hearer, reader or viewer to determine for themselves, or may be explicitly encapsulated in a maxim...
principles that apply values and judgments to the practice of medicine.
- Biomedical EngineeringBiomedical engineeringBiomedical Engineering is the application of engineering principles and design concepts to medicine and biology. This field seeks to close the gap between engineering and medicine: It combines the design and problem solving skills of engineering with medical and biological sciences to improve...
is a field dealing with the application of engineeringEngineeringEngineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
principles to medical practice.
- Clinical pharmacologyClinical pharmacologyClinical pharmacology is the science of drugs and their clinical use. It is underpinned by the basic science of pharmacology, with added focus on the application of pharmacological principles and methods in the real world...
is concerned with how systems of therapeutics interact with patients.
- Conservation medicineConservation medicineConservation medicine is an emerging, interdisciplinary field that studies the relationship between human and animal health, and environmental conditions. Also known as ecological medicine, environmental medicine, or medical geology....
studies the relationship between human and animal health, and environmental conditions. Also known as ecological medicine, environmental medicineEnvironmental medicineEnvironmental medicine is a multidisciplinary field involving medicine, environmental science, chemistry and others. It may be viewed as the medical branch of the broader field of environmental health. The scope of this field involves studying the interactions between environment and human health,...
, or medical geologyMedical geologyMedical geology is an emerging interdisciplinary scientific field consisting of those aspects of geology as they affect human, animal and plant health.Examples include:*Lead and other heavy metal exposure resulting from dust and other particulates...
- Disaster medicineDisaster medicineDisaster medicine is the area of physician medical specialization serving the dual areas of providing medical care to disaster survivors and providing medically related disaster preparation, disaster planning, disaster response and disaster recovery leadership throughout the disaster life cycle...
deals with medical aspects of emergency preparedness, disaster mitigation and management.
- Diving medicineDiving medicineDiving medicine, also called undersea and hyperbaric medicine , is the diagnosis, treatment and prevention of conditions caused by humans entering the undersea environment...
(or hyperbaric medicine) is the prevention and treatment of diving-related problems.
- Evolutionary medicineEvolutionary medicineEvolutionary medicine or Darwinian medicine is the application of modern evolutionary theory to understanding health and disease. It provides a complementary scientific approach to the present mechanistic explanations that dominate medical science, and particularly modern medical education...
is a perspective on medicine derived through applying evolutionary theoryEvolutionEvolution is any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.Life on Earth...
- Forensic medicine deals with medical questions in legal context, such as determination of the time and cause of death.
- Gender-based medicineGender-based medicineGender-based medicine or simply gender medicine is the field of medicine that studies the biological and physiological differences between the human sexes and how that affects differences in disease. Traditionally, medical research has mostly been conducted using the male body as the basis for...
studies the biological and physiological differences between the human sexes and how that affects differences in disease.
- Hospice and Palliative MedicineHospice and Palliative MedicineHospice and Palliative Medicine is a formal subspecialty of medicine in the United States that focuses on symptom management, relief of suffering and end-of-life care...
is a relatively modern branch of clinical medicine that deals with pain and symptom relief and emotional support in patients with terminal illnessTerminal illnessTerminal illness is a medical term popularized in the 20th century to describe a disease that cannot be cured or adequately treated and that is reasonably expected to result in the death of the patient within a short period of time. This term is more commonly used for progressive diseases such as...
es including cancer and heart failure.
- Hospital medicineHospital medicineHospital medicine in the United States is the discipline concerned with the medical care of acutely ill hospitalized patients. Physicians whose primary professional focus is hospital medicine are called hospitalists; this type of medical practice has extended beyond the US into Canada...
is the general medical care of hospitalized patients. Physicians whose primary professional focus is hospital medicine are called hospitalists in the USA and Canada. The term Most Responsible Physician (MRP) or attending physician is also used interchangeably to describe this role.
- Laser medicineLaser medicineLaser medicine is the use of various types of lasers in medical diagnosis, treatment, or therapy. Types of lasers used in medicine include in principle any laser design, especially:* CO2 lasers* diode lasers* dye lasers* excimer lasers* fiber lasers...
involves the use of lasers in the diagnostics and/or treatment of various conditions.
- Medical humanitiesMedical humanitiesMedical humanities is an interdisciplinary field of medicine which includes the humanities , social science , and the arts and their application to medical education and practice...
includes the humanitiesHumanitiesThe humanities are academic disciplines that study the human condition, using methods that are primarily analytical, critical, or speculative, as distinguished from the mainly empirical approaches of the natural sciences....
(literatureLiteratureLiterature is the art of written works, and is not bound to published sources...
, philosophyPhilosophyPhilosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...
, ethicsEthicsEthics, also known as moral philosophy, is a branch of philosophy that addresses questions about morality—that is, concepts such as good and evil, right and wrong, virtue and vice, justice and crime, etc.Major branches of ethics include:...
, history and religion), social science (anthropologyAnthropologyAnthropology is the study of humanity. It has origins in the humanities, the natural sciences, and the social sciences. The term "anthropology" is from the Greek anthrōpos , "man", understood to mean mankind or humanity, and -logia , "discourse" or "study", and was first used in 1501 by German...
, cultural studiesCultural studiesCultural studies is an academic field grounded in critical theory and literary criticism. It generally concerns the political nature of contemporary culture, as well as its historical foundations, conflicts, and defining traits. It is, to this extent, largely distinguished from cultural...
, psychologyPsychologyPsychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...
, sociologySociologySociology is the study of society. It is a social science—a term with which it is sometimes synonymous—which uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social activity...
), and the arts (literatureLiteratureLiterature is the art of written works, and is not bound to published sources...
, theater, film, and visual artsVisual artsThe visual arts are art forms that create works which are primarily visual in nature, such as ceramics, drawing, painting, sculpture, printmaking, design, crafts, and often modern visual arts and architecture...
) and their application to medical educationMedical educationMedical education is education related to the practice of being a medical practitioner, either the initial training to become a doctor or additional training thereafter ....
- Medical informatics, medical computer science, medical information and eHealthEHealtheHealth is a relatively recent term for healthcare practice supported by electronic processes and communication, dating back to at least 1999...
are relatively recent fields that deal with the application of computers and information technologyInformation technologyInformation technology is the acquisition, processing, storage and dissemination of vocal, pictorial, textual and numerical information by a microelectronics-based combination of computing and telecommunications...
- Nosology is the classification of diseases for various purposes.
- NosokineticsNosokineticsNosokinetics is the science/subject of measuring and modelling the process of care in health and social care systems. Nosokinetics brings together the Greek words for noso: disease and kinetics: movement....
is the science/subject of measuring and modelling the process of care in health and social care systems.
- Pain managementPain managementPain management is a branch of medicine employing an interdisciplinary approach for easing the suffering and improving the quality of life of those living with pain. The typical pain management team includes medical practitioners, clinical psychologists, physiotherapists, occupational therapists,...
(also called pain medicine, or algiatry) is the medical discipline concerned with the relief of pain.
- PharmacogenomicsPharmacogenomicsPharmacogenomics is the branch of pharmacology which deals with the influence of genetic variation on drug response in patients by correlating gene expression or single-nucleotide polymorphisms with a drug's efficacy or toxicity...
is a form of individualized medicine.
- Sexual medicineSexual medicineSexual medicine is a medical specialty that deals with sexual health. At times heavily influenced by current local views on morality, with heavy cultural overlay, in broad terms this specialty is concerned with diagnosing, assessing and treating all aspects which relate to sexuality.Issues can be...
is concerned with diagnosing, assessing and treating all disorders related to sexuality.
- Sports medicineSports medicineSports medicine is a branch of medicine that deals with physical fitness, treatment and prevention of injuries related to sports and exercise...
deals with the treatment and preventive care of athletes, amateurAmateurAn amateur is generally considered a person attached to a particular pursuit, study, or science, without pay and often without formal training....
and professionalProfessionalA professional is a person who is paid to undertake a specialised set of tasks and to complete them for a fee. The traditional professions were doctors, lawyers, clergymen, and commissioned military officers. Today, the term is applied to estate agents, surveyors , environmental scientists,...
. The team includes specialty physicians and surgeons, athletic trainers, physical therapists, coachCoach (sport)In sports, a coach is an individual involved in the direction, instruction and training of the operations of a sports team or of individual sportspeople.-Staff:...
es, other personnel, and, of course, the athlete.
- Therapeutics is the field, more commonly referenced in earlier periods of history, of the various remedies that can be used to treat disease and promote health http://www.britannica.com/eb/article-9106176?query=Therapeutics&ct=.
- Travel medicineTravel medicineTravel medicine or emporiatrics is the branch of medicine that deals with the prevention and management of health problems of international travelers.-Globalization and travel:...
or emporiatrics deals with health problems of international travelers or travelers across highly different environments.
- Urgent careUrgent careUrgent care is the delivery of ambulatory care in a facility dedicated to the delivery of medical care outside of a hospital emergency department, usually on an unscheduled, walk-in basis. Urgent care centers are primarily used to treat patients who have an injury or illness that requires immediate...
focuses on delivery of unscheduled, walk-in care outside of the hospital emergency department for injuries and illnesses that are not severe enough to require care in an emergency department. In some jurisdictions this function is combined with the emergency room.
- Veterinary medicineVeterinary medicineVeterinary Medicine is the branch of science that deals with the prevention, diagnosis and treatment of disease, disorder and injury in non-human animals...
; veterinarians apply similar techniques as physicians to the care of animals.
- Wilderness medicineWilderness medicineWilderness medicine is defined by difficult patient access, limited equipment, and environmental extremes. Today, wilderness or expedition medicine is practiced by Wilderness First Responders, Wilderness EMTs, Remote/Offshore/Wilderness Paramedics and Physicians on expeditions, in outdoor...
entails the practice of medicine in the wild, where conventional medical facilities may not be available.
- Many other health science fields, e.g. dietetics
, followed by a period of supervised practice or internship
, and/or residency
. This can be followed by postgraduate vocational training. A variety of teaching methods have been employed in medical education, still itself a focus of active research.
Many regulatory authorities require continuing medical education
, since knowledge, techniques and medical technology continue to evolve at a rapid rate.
Legal controlsIn most countries, it is a legal requirement for a medical doctor to be licensed or registered. In general, this entails a medical degree from a university and accreditation by a medical board or an equivalent national organization, which may ask the applicant to pass exams. This restricts the considerable legal authority of the medical profession to physicians that are trained and qualified by national standards. It is also intended as an assurance to patients and as a safeguard against charlatan
s that practice inadequate medicine for personal gain. While the laws generally require medical doctors to be trained in "evidence based", Western, or Hippocratic Medicine, they are not intended to discourage different paradigms of health.
Doctors who are negligent or intentionally harmful in their care of patients can face charges of medical malpractice
and be subject to civil, criminal, or professional sanctions.
ControversyThe Catholic social theorist Ivan Illich
subjected contemporary western medicine to detailed attack in his Medical Nemesis, first published in 1975. He argued that the medicalization
in recent decades of so many of life's vicissitudes — birth and death, for example — frequently caused more harm than good and rendered many people in effect lifelong patients. He marshalled a body of statistics to show what he considered the shocking extent of post-operative side-effects and drug-induced illness in advanced industrial society
. He was the first to introduce to a wider public the notion of iatrogenesis
. Others have since voiced similar views, but none so trenchantly, perhaps, as Illich.
Through the course of the twentieth century, healthcare providers focused increasingly on the technology that was enabling them to make dramatic improvements in patients' health. The ensuing development of a more mechanistic, detached practice, with the perception of an attendant loss of patient-focused care, known as the medical model
of health, led to criticisms that medicine was neglecting a holistic model. The inability of modern medicine to properly address some common complaints continues to prompt many people to seek support from alternative medicine
. Although most alternative approaches lack scientific validation, some, notably acupuncture for some conditions and certain herbs, are backed by evidence.
s and overmedication
are also the focus of complaints and negative coverage. Practitioners of human factors
believe that there is much that medicine may usefully gain by emulating concepts in aviation safety, where it is recognized that it is dangerous to place too much responsibility on one "superhuman" individual and expect him or her not to make error
s. Reporting systems and checking mechanisms are becoming more common in identifying sources of error and improving practice. Clinical versus statistical, algorithmic diagnostic methods were famously examined in psychiatric practice in a 1954 book by Paul E. Meehl
, which found statistical methods superior. A 2000 meta-analysis
comparing these methods in both psychology and medicine found that statistical or "mechanical" diagnostic methods were, in general, although not always, superior.
Disparities in quality of care given are often an additional cause of controversy. For example, elderly mentally ill patients received poorer care during hospitalization in a 2008 study. Rural poor African-American men were used in a study of syphilis that denied them basic medical care.
Honors and awardsThe highest honor awarded in medicine is the Nobel Prize in Medicine, awarded since 1901 by the Nobel Assembly at Karolinska Institutet
PatronageThere are a number of patron saints
for physicians, the most important of whom are Saint Luke the Evangelist the physician and disciple of Christ
, Saints Cosmas and Damian
(3rd-century physicians from Syria
), and Saint Pantaleon
(4th-century physician from Nicomedia
). Archangel Raphael is also considered a patron saint of physicians.
The patron saints
for surgeons are Saint Luke the Evangelist, the physician and disciple of Christ
, Saints Cosmas and Damian
(3rd-century physicians from Syria
), Saint Quentin
(3rd-century saint from France), Saint Foillan (7th-century saint from Ireland
), and Saint Roch (14th-century saint from France).