Uremia Classification and external resources
Urea
ICD-10	R39.2
ICD-9	585-586, 788.9
DiseasesDB	26060
eMedicine	med/2341
MeSH	D014511

Uremia 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.¹

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. It is usually diagnosed in kidney dialysis patients when the glomerular filtration rate, a measure of kidney function, is below 50% of normal.²

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 fibrinous 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).

Causes

Besides renal failure, 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. hypotension, cardiac failure)
  • urinary outflow obstruction

• dehydration
• chronic infection of the kidney, such as chronic pyelonephritis

References