Creatinine Clearance Test

A creatinine clearance test is performed to evaluate the functioning of kidneys when kidney diseases are suspected.

Common symptoms and signs of kidney disease include:

• Swelling or puffiness around the face and abdomen and in the ankles and wrists 
• Reduced urine output
• Foamy, coffee-coloured or blood-stained urine
• Urination issues and altered frequency of urination
• Passing of proteins in the urine
• High blood pressure
• Nausea
• Vomiting
• Muscle cramps
• Itches and skin rash
• Altered sleep patterns

The test is also performed in people having chronic kidney disease or congestive heart failure for monitoring the progress of the disease and assessing disease severity. It is also useful in determining the need for dialysis.

No special preparation is needed before this test. Blood sample may be collected either before starting the urine collection or at the end of the urine collection.

Blood test: An experienced laboratory specialist will collect a blood sample from a vein in your arm by inserting a small needle. A small quantity of blood will be withdrawn into a sterile vial or a test tube. A momentary pricking pain is felt when the needle goes in the vein.

Your height and weight may be measured as these fators are needed to provide accurate calculations.

There is a minimal risk of pain, light-headedness and bruising at the site of injection associated with the test. However, at most times, these symptoms disappear quickly. Rarely, an infection may occur at the site of blood withdrawal.

Urine test: A 24-hour urine sample is collected for this test. The first urine of the day needs to be passed in the pot, and thereafter all samples need to be collected in the container until the following morning.

Creatinine clearance is evaluated as millilitres per minute (mL/min).

Normal results: Normal levels of creatinine clearance are different for males and females. The normal levels for males are 97-137 mL/min, females are 88-128 mL/min and newborns are 40-65 mL/min.

After the age of 40 years, at every addition of a decade, the creatinine clearance level drops by 6.5 mL/min.

Abnormal results:

Low levels:

The causes of low levels of creatinine clearance include

• Kidney failure (Read more: Acute kidney failure symptoms)
• Kidney damage
• Reduced blood flow to kidneys
• Severe dehydration (loss of body fluids)
• Bladder obstruction
• Congestive heart failure
• Glomerulonephritis (due to infection or autoimmune diseases)
• Pyelonephritis (infection of kidneys caused by bacteria)
• Shock
• Diabetes

Drugs, such as aminoglycosides, cisplatin, cephalosporins and cimetidine, are known to reduce creatinine clearance levels.

Increased levels of creatinine clearance are seen during pregnancy, after exercising and in a high protein diet, but it does not signify any major health issue and is not used for monitoring these conditions. Also, diuretics are known to increase creatinine clearance levels.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.