24-hour urine copper test

Definition

The 24-hour urine copper test measures the amount of copper in a urine sample.

Alternative Names

Why the Test is Performed

Your doctor may order this test if you have signs of Wilson's disease, a genetic disorder that affects how the body processes copper.

How the Test is Performed

A 24-hour urine sample is needed.

• On day 1, urinate into the toilet upon arising in the morning.
• Collect all subsequent urine (in a special container provided by your doctor's office or lab) for the next 24 hours.
• On day 2, urinate into the container in the morning upon arising.
• Cap the container. Keep it in the refrigerator or a cool place during the collection period. Label the container with your name, the date, the time of completion, and return it as instructed.

For infants, thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on the infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Diaper as usual over the secured bag.

This procedure may take a couple of attempts -- lively infants can displace the bag, causing the specimen to be absorbed by the diaper. The infant should be checked frequently and the bag changed after the infant has urinated into the bag. The urine is drained into the container for transport to the laboratory.

Deliver it to the laboratory or your health care provider as soon as possible upon completion. A laboratory specialist will determine how much copper is in the sample.

How to Prepare for the Test

No special preparation is necessary for this test, but if the collection is being taken from an infant, a couple of extra collection bags may be necessary.

How the Test Will Feel

The test involves only normal urination, and there is no discomfort.

Risks

There are no risks associated with providing a urine sample.

Risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Normal Results

The normal range is 10 to 30 micrograms per 24 hours.

Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What Abnormal Results Mean

An abnormal result means you have a higher than normal level of copper. This may be due to:

• Biliary cirrhosis
• Chronic active hepatitis
• Wilson's disease