Serum Creatinine

Specimen Required

3-5cc Clotted Blood or Serum

Fasting Required

Purpose of the Serum Creatinine Test

To determine if your kidneys work normally and to monitor treatment for kidney disease

When this Serum Creatinine test is required

Creatinine may be part of a routine blood test, widely used when someone has non-specific health complaints, or when your doctor suspects your kidneys are not working properly.Some signs and symptoms of kidney dysfunction include: Fatigue, lack of concentration, poor appetite or trouble sleeping Swelling or puffiness, particularly around the eyes or in the face, wrists, abdomen, thighs or ankles Urine that is foamy, bloody, or coffee-coloured A decrease in the amount of urine Problems urinating, such as a burning feeling or abnormal discharge during urination, or a change in the frequency of urination, especially at night Mid-back pain (flank), below the ribs, near where the kidneys are located High blood pressureThe test is also used to monitor treatment of kidney disease or to monitor kidney function while you are on certain drugs.

What the Serum Creatinine Test Detects

This test measures the amount of creatinine in your blood and/or urine. Creatinine is a waste product produced in your muscles from the breakdown of a compound called creatine. Creatine is part of the cycle that produces energy needed to contract your muscles. Both creatine and creatinine are produced by the body at a relatively constant rate. Almost all creatinine is excreted by the kidneys, so blood levels are a good measure of…This test measures the amount of creatinine in your blood and/or urine. Creatinine is a waste product produced in your muscles from the breakdown of a compound called creatine. Creatine is part of the cycle that produces energy needed to contract your muscles. Both creatine and creatinine are produced by the body at a relatively constant rate. Almost all creatinine is excreted by the kidneys, so blood levels are a good measure of how well your kidneys are working. The quantity produced depends on the sex, size or age of the person and their muscle mass. For this reason, creatinine concentrations will be slightly higher in men than in women and children. Urine creatinine test is a measure of the amount of creatinine in urine. This test can be performed on a “spot” urine sample or a 24-hour urine collection, depending on which test is being requested by your clinician. Less commonly, 24-hour urine creatinine test may be used to calculate creatinine clearance. With the exception of few clinical scenarios, creatinine clearance test has largely been replaced by glomerular filtration rate (GFR) measurement. See MoreSee Less

Preparation for the Serum Creatinine Test

None

Sample Requirements

A blood sample is taken from a vein in the arm. Spot urine or 24-hour urine sample collection is needed for the measurement of urine creatinine.

Additional Notes

Since creatinine levels are in proportion to muscle mass, women tend to have lower levels than men. In general, creatinine levels will stay the same if you eat a normal diet. However, eating large amounts of meat may cause short-lived increases in blood creatinine levels. Taking creatine supplements may also increase creatinine concentration.There are a few drugs that interfere with the creatinine test, although there are some drugs that can cause some impairment in kidney function. Your creatinine levels may be monitored if you are taking one of these drugs.

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