Uremia

In medicine, uremia is the presence in the blood of high levels of urea (one of the primary components of urine). It can be defined as an excess in the blood of such end products of amino acid and protein metabolism as urea and creatinine, which would normally be excreted in the urine. By comparison, uremic syndrome can be defined as the terminal clinical manifestation of kidney failure (also called renal failure). It is the signs, symptoms and results from laboratory tests which result from inadequate excretory, regulatory, and endocrine function of the kidneys. The terms uremia and uremic syndrome have been used interchangeably to denote a very high plasma urea concentration that is the result of renal failure. The former denotation will be used for the rest of the article. A similar, less severe condition involving high levels of urea is azotemia, in which the abnormality can be measured chemically but is not yet so severe as to produce symptoms. Uremia is thus the collection of the pathological and symptomatic manifestations of severe azotemia. There is no specific time for the onset of uremia for people with progressive loss of kidney function. People with kidney function below 50% (i.e. a glomerular filtration rate [GFR] between 50 and 60 mL/min) and over 30 years of age may have uremia to a degree. This means an estimated 8 million people in the United States with a GFR of less than 60 mL/min have uremic symptoms. The symptoms, such as fatigue, can be very vague, making the diagnosis of impaired kidney function difficult. Treatment can be by dialysis or a kidney transplant, though some patients choose to pursue symptom control and conservative care instead.