In medicine

Medicine

Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....

, a disease is considered asymptomatic if a patient is a carrier for a disease or infection but experiences no symptoms. A condition might be asymptomatic if it fails to show the noticeable symptom

Symptom

A symptom is a departure from normal function or feeling which is noticed by a patient, indicating the presence of disease or abnormality...

s with which it is usually associated. Asymptomatic infections are also called subclinical infection

Subclinical infection

A subclinical infection is the asymptomatic carrying of an by an individual of an agent that usually is a pathogen causing illness, at least in some individuals. Many pathogens spread by being silently carried in this way by some of their host population...

s. The term clinically silent is also used.

Knowing that a condition is asymptomatic is important because:

• It may develop symptoms later and so require watch and wait or early treatment.
• It may resolve itself or be benign
  Benign
  A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...
  
  .
• It is required that a person undergoes treatment so it does not cause later medical problems such as high blood pressure and hyperlipidaemia.
• Be alert to possible problems: asymptomatic hypothyroidism
  Hypothyroidism
  Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...
  
   makes a person vulnerable to Wernicke-Korsakoff syndrome
  Wernicke-Korsakoff syndrome
  Wernicke–Korsakoff syndrome is a manifestation of thiamine deficiency, or beriberi. This is usually secondary to alcohol abuse...
  
   or beri-beri following intravenous glucose.
• The affected person may be infectious and unknowingly spread
  Subclinical infection
  A subclinical infection is the asymptomatic carrying of an by an individual of an agent that usually is a pathogen causing illness, at least in some individuals. Many pathogens spread by being silently carried in this way by some of their host population...
  
   the infection to others.

Conditions

Asymptomatic conditions may not be discovered until the patient undergoes medical tests (X-ray

X-ray

X-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 or other investigations). Some people may remain asymptomatic for a remarkably long period of time; such as people with some forms of cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

. If a patient is asymptomatic, precautionary steps must be taken.

A patient's individual genetic makeup may delay or prevent the onset of symptoms.

List

These are conditions for which there is a sufficient number of documented individuals that are asymptomatic that it is clinically noted. For a complete list of asymptomatic infections see subclinical infection