Uremia
Encyclopedia
Uremia or uraemia is a term used to loosely describe the illness accompanying kidney failure
(also called renal failure), in particular the nitrogenous waste products associated with the failure of this organ.
In kidney failure, urea
and other waste products, which are normally excreted into the urine
, are retained in the blood. Early symptoms include anorexia
and lethargy, and late symptoms can include decreased mental acuity and coma. Other symptoms include fatigue, nausea, vomiting, cold, bone pain, itch, shortness of breath, and seizures. It is usually diagnosed in kidney dialysis patients when the glomerular filtration rate, a measure of kidney function, is below 50% of normal.
Azotemia
is another word that refers to high levels of urea, but is used primarily when the abnormality can be measured chemically but is not yet so severe as to produce symptoms. Uremia can also result in uremic pericarditis
. There are many dysfunctions caused by uremia affecting many systems of the body, such as blood (lower levels of erythropoietin), sex (lower levels of testosterone/estrogen), and bones (osteoporosis and metastatic calcifications). Uremia can also cause decreased peripheral conversion of T4 to T3, producing a functionally hypothyroid state.
Endocrine and metabolic
Other
Because uremia mostly is a consequence of kidney failure, its signs and symptoms often occur concomitantly with other ones signs and symptoms of kidney failure, such as hypertension due to volume overload, hypocalcemic tetany, and anemia due to erythropoietin deficiency. These, however, are not signs or symptoms of uremia. Still, it is not certain that the symptoms currently associated with uremia actually are caused by excess urea, as one study showed that uremic symptoms were relieved by initiation of dialysis, even when urea was added to the dialysate to maintain the blood urea nitrogen level at approximately 90 mg per deciliter (that is, approximately 32 mmol per liter).
, the level of urea in the blood can also be increased by:
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
(also called renal failure), in particular the nitrogenous waste products associated with the failure of this organ.
In kidney failure, urea
Urea
Urea or carbamide is an organic compound with the chemical formula CO2. The molecule has two —NH2 groups joined by a carbonyl functional group....
and other waste products, which are normally excreted into the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
, are retained in the blood. Early symptoms include anorexia
Anorexia (symptom)
Anorexia is the decreased sensation of appetite...
and lethargy, and late symptoms can include decreased mental acuity and coma. Other symptoms include fatigue, nausea, vomiting, cold, bone pain, itch, shortness of breath, and seizures. It is usually diagnosed in kidney dialysis patients when the glomerular filtration rate, a measure of kidney function, is below 50% of normal.
Azotemia
Azotemia
Azotemia is a medical condition characterized by abnormally high levels of nitrogen-containing compounds, such as urea, creatinine, various body waste compounds, and other nitrogen-rich compounds in the blood...
is another word that refers to high levels of urea, but is used primarily when the abnormality can be measured chemically but is not yet so severe as to produce symptoms. Uremia can also result in uremic pericarditis
Uremic pericarditis
-Presentation:Fibrinous pericarditis is an exudative inflammation. The pericardium is infiltrated by the fibrinous exudate. This consists of fibrin strands and leukocytes. Fibrin describes an amorphous, eosinophilic network. Leukocytes are found within the fibrin deposits and intrapericardic....
. There are many dysfunctions caused by uremia affecting many systems of the body, such as blood (lower levels of erythropoietin), sex (lower levels of testosterone/estrogen), and bones (osteoporosis and metastatic calcifications). Uremia can also cause decreased peripheral conversion of T4 to T3, producing a functionally hypothyroid state.
Physical signs, symptoms, and laboratory findings
Neural and muscular- FatigueFatigueFatigue may refer to:*Fatigue , structural damage from repeated loading*Fatigue , a state of physical and/or mental weakness*Fatigue , safety implications of tiredness...
- Peripheral neuropathyPeripheral neuropathyPeripheral neuropathy is the term for damage to nerves of the peripheral nervous system, which may be caused either by diseases of or trauma to the nerve or the side-effects of systemic illness....
- Decreased mentalMentalMental, a word referring to aspects of, or things related to, the mind; or in anatomy, the skull, e.g. the mental foramen, can also mean:* a slang, pejorative term used to describe people who act like lunatics, which is itself an outdated term for people with mental disorders* Mental , a 2009...
acuity - Seizures
- AnorexiaAnorexia (symptom)Anorexia is the decreased sensation of appetite...
- NauseaNauseaNausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...
- Decreased tasteTasteTaste is one of the traditional five senses. It refers to the ability to detect the flavor of substances such as food, certain minerals, and poisons, etc....
and smellOlfactionOlfaction is the sense of smell. This sense is mediated by specialized sensory cells of the nasal cavity of vertebrates, and, by analogy, sensory cells of the antennae of invertebrates... - CrampCrampCramps are unpleasant, often painful sensations caused by muscle contraction or over shortening. Common causes of skeletal muscle cramps include muscle fatigue, low sodium, and low potassium...
s - Restless legsRestless legs syndromeRestless legs syndrome or Willis-Ekbom disease is a neurological disorder characterized by an irresistible urge to move one's body to stop uncomfortable or odd sensations. It most commonly affects the legs, but can affect the arms, torso, and even phantom limbs...
, potentially due to decreased muscle membrane potentialMembrane potentialMembrane potential is the difference in electrical potential between the interior and exterior of a biological cell. All animal cells are surrounded by a plasma membrane composed of a lipid bilayer with a variety of types of proteins embedded in it... - Sleep disturbance
- ComaComaIn medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
Endocrine and metabolic
- Amenorrhea
- Sexual dysfunctionSexual dysfunctionSexual dysfunction or sexual malfunction refers to a difficulty experienced by an individual or a couple during any stage of a normal sexual activity, including desire, arousal or orgasm....
- Reduced body temperature
- Altered levels of amino acidAmino acidAmino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...
s - Bone disease by hyperphosphatemiaHyperphosphatemiaHyperphosphatemia is an electrolyte disturbance in which there is an abnormally elevated level of phosphate in the blood. Often, calcium levels are lowered due to precipitation of phosphate with the calcium in tissues.-Signs and symptoms:...
, hyperparathyroidismHyperparathyroidismHyperparathyroidism is overactivity of the parathyroid glands resulting in excess production of parathyroid hormone . The parathyroid hormone regulates calcium and phosphate levels and helps to maintain these levels...
and vitamin D deficiency - Reduced basal metabolic rateBasal metabolic rateBasal Metabolic Rate , and the closely related resting metabolic rate , is the amount of daily energy expended by humans and other animals at rest. Rest is defined as existing in a neutrally temperate environment while in the post-absorptive state...
- Insulin resistanceInsulin resistanceInsulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
- Increased muscle protein catabolismProtein catabolismProtein catabolism is the breakdown of proteins into amino acids and simple derivative compounds, for transport into the cell through the plasma membrane and ultimately for the polymerisation into new proteins via the use of ribonucleic acids and ribosomes...
Other
- SerositisSerositisSerositis refers to inflammation of the serous tissues of the body, the tissues lining the lungs , heart , and the inner lining of the abdomen and organs within...
, including pericarditisPericarditisPericarditis is an inflammation of the pericardium . A characteristic chest pain is often present.The causes of pericarditis are varied, including viral infections of the pericardium, idiopathic causes, uremic pericarditis, bacterial infections of the precardium Pericarditis is an inflammation of... - Itching
- Hiccups
- Oxidative stressOxidative stressOxidative stress represents an imbalance between the production and manifestation of reactive oxygen species and a biological system's ability to readily detoxify the reactive intermediates or to repair the resulting damage...
- granulocyte and lymphocyte dysfunction
- Platelet dysfunction
Because uremia mostly is a consequence of kidney failure, its signs and symptoms often occur concomitantly with other ones signs and symptoms of kidney failure, such as hypertension due to volume overload, hypocalcemic tetany, and anemia due to erythropoietin deficiency. These, however, are not signs or symptoms of uremia. Still, it is not certain that the symptoms currently associated with uremia actually are caused by excess urea, as one study showed that uremic symptoms were relieved by initiation of dialysis, even when urea was added to the dialysate to maintain the blood urea nitrogen level at approximately 90 mg per deciliter (that is, approximately 32 mmol per liter).
Causes
Besides renal failureRenal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
, the level of urea in the blood can also be increased by:
- increased production of urea in the liver, due to:
- high protein diet
- increased protein breakdown (surgery, infection, trauma, cancer)
- gastrointestinal bleeding
- drugs (e.g. tetracyclines and corticosteroids)
- decreased elimination of urea, due to:
- decreased blood flow through kidney (e.g. hypotensionHypotensionIn physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
, cardiac failure) - urinary outflow obstruction
- bladder rupture
- decreased blood flow through kidney (e.g. hypotension
- dehydration
- chronic infection of the kidney such as chronic pyelonephritisPyelonephritisPyelonephritis is an ascending urinary tract infection that has reached the pyelum or pelvis of the kidney. It is a form of nephritis that is also referred to as pyelitis...