Serum Urea

Specimen Required

3-5cc Clotted Blood or Serum

Fasting Required

Purpose of the Serum Urea Test

To evaluate kidney function or to monitor the effectiveness of dialysis

When this Serum Urea test is required

Urea may alsonbe used in a panel of tests: when someone has non-specific illness, as part of a routine group of tests (often called “urea and electrolytes” (U&E), to check how the kidneys are functioning before starting to take certain drugs.Urea is often requested with creatinine: if kidney problems are suspected, to monitor treatment of kidney disease, or to monitor kidney function while someone is on certain drugsSome symptoms and signs of kidney dysfunction include: Tiredness, lack of concentration, poor appetite, poor sleep Swelling or puffiness (oedema) around the eyes, wrists, ankles or tummy Urine that is foamy, blood strained or coffee-coloured A decrease in the amount of urine Problems urinating such as a burning sensation, abnormal discharge during urination or a change in the frequency of urination especially at night Mid-back pain below the ribs where the kidneys are located High blood pressure

What the Serum Urea Test Detects

Urea is the final breakdown product of the amino acids found in proteins. Nitrogen in the form of ammonia is produced in the liver when protein is broken down. The nitrogen combines with other chemicals in the liver to form the waste product urea. The urea is released into the bloodstream and carried to the kidneys where it is filtered out of the blood and excreted in the urine. Healthy kidneys remove more than 90% of the urea the body produces, so blood levels can show how well your kidneys are working.Most diseases that affect the kidneys or liver can affect the amount of urea present in the blood. If increased amounts of urea are produced by the liver or decreased amounts are removed by the kidneys then blood urea concentrations will rise. If significant liver damage or disease reduces the production of urea then urea concentrations may fall.

Preparation for the Serum Urea Test

No test preparation is needed

Sample Requirements

A blood sample taken from a vein in the arm

Additional Notes

Urea levels increase with age and also with the amount of protein in your diet. High-protein diets may cause abnormally high urea levels. Very low-protein diets can cause abnormally low urea levels. Lower urea levels are also seen in infants and small children.Drugs that can impair kidney function may increase urea levels. Your urea and creatinine may be monitored if you are on certain drugs.

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