What is the Urea test?

The Urea blood test, along with the Creatinine blood test, is used to evaluate renal function. Urea is formed in the liver deriving from the protein breakdown. It then passes to blood circulation and is eliminated from the body through kidneys. If kidneys do not function properly or the body organism uses large amounts of protein, urea levels increase in the blood. In case of  severe liver disease, the exactly opposite occurs, i.e. urea levels reduce in the blood.

When is the Urea test performed?

The Urea test is useful when there is suspected renal dysfunction. Some of the symptoms are:

  • Weakness, fatigue, concentration deficit, drowsiness.
  • Oedema of ankles, abdomen, around the eyes.
  • Brownish urine.
  • Reduction of urine output.
  • Pain in the renal region.
  • High blood pressure.

It is also used:

  • to monitor patients under treatment for established renal disease
  • to monitor patients taking drugs that may have harmful effect on kidneys
  • within the context of lab testing in emergency patients
  • as a routine check-up
  • to evaluate renal function before the onset of some pharmaceutical therapy

What preparation is needed for the Urea test?

There is no special preparation required. To evaluate urea levels all that is needed is simple sampling of a small blood specimen.

How is the Urea test performed?

Once obtained, the blood specimen is taken to the biochemical laboratory. Urea in the blood sample is measured with the use of special analyzers.

How are the results of the Urea test interpreted?

Normal blood urea values are 10-50 mg/dl (there may be small differences from lab to lab). High urea levels may indicate renal impairment (acute or chronic). Also, urea levels may increase due to heart failure, myocardium infarction, severe burn, gastrointestinal hemorrhage (bleeding), urinary tract obstruction or dehydration. Low urea levels are more rare and may be due to normal gestation, malnutrition or severe liver disease.