Urea Health Dictionary

A waste product of the breakdown of proteins by the liver that is transported to the kidneys and eliminated in the urine.

Urea is also formed in the body from the breakdown of cell proteins.

Kidney failure impairs the kidneys’ ability to eliminate urea and leads to uraemia; measurement of blood levels of urea is a routine kidney function test.

Urea is used in various creams and ointments to treat skin disorders such as psoriasis.

Urea, or carbomide, is a crystalline substance of the chemical formula CO(NH2)2, which is very soluble in water or alcohol. It is the chief waste product discharged from the body in the URINE, being formed in the liver and carried to the kidneys in the blood. The amount varies considerably with the quantity and nature of the food taken, rising greatly upon an animal (protein) dietary. It also rises during the continuance of a fever. The average amount excreted daily by a healthy adult on a mixed diet is about 33–35 grams. Kidney failure causes a rise in the concentration of urea in the blood (see URAEMIA; KIDNEYS, DISEASES OF).

Urea is usually administered for its diuretic action (see DIURETICS), and also as a test of kidney action, in doses of 5–15 grams. It is used, too, as a cream in the treatment of certain skin diseases, characterised by a dry skin.

Urea is rapidly changed, by a yeast-like micro-organism, into carbonate of ammonia – the cause of the ammoniacal smell associated with INCONTINENCE and inadequately cleaned toilets.

n. the main breakdown product of protein metabolism. It is the chemical form in which unrequired nitrogen is excreted by the body in the urine. Urea is formed in the liver from ammonia and carbon dioxide in a series of enzyme-mediated reactions (the urea cycle). Accumulation of urea in the bloodstream together with other nitrogenous compounds is due to kidney failure and gives rise to *uraemia.