Uric acid, urine

• On day 1, urinate into the toilet upon arising in the morning.
• Collect all subsequent urine (in a special container) 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.

Infant:
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 your 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. Place a diaper over the infant (bag and all). The infant should be checked frequently and the bag changed after the infant has urinated into the bag. For active infants, this procedure may take a couple of attempts--lively infants can displace the bag, causing an inability to obtain the specimen. 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.

How to Prepare:
The health care provider may advise you to discontinue drugs that can affect the test (see "special considerations").

If the collection is being taken from an infant, a couple of extra collection bags may be necessary.

How it Feels:
The test involves only normal urination, and there is no discomfort.

Why this Test is Performed:
The most common reason for measuring uric acid levels is in the diagnosis or treatment of gout , because gout results from crystallization of uric acid crystals in joints. Some kidney stones are also composed of uric acid.

Uric acid is the end-product of purine catabolism. Purines (such as adenine and guanine) are amino acids (the "building blocks" of proteins ). Purines are components of nucleotides, which are part of the nucleic acids (such as RNA and DNA).

Normal Values:
250 to 750 mg/24-hours

Note: mg/24 hr = milligrams per 24-hours

Abnormal Results:
Greater-than-normal urinary uric acid levels may indicate:

• chronic myelogenous leukemia
• gout
• high purine diet
• liver disease
• polycythemia vera

Lower-than-normal urinary uric acid levels may indicate:

• chronic alcohol ingestion
• chronic glomerulonephritis
• lead poisoning
• urinary obstruction

Cost:
The estimated cost is $25.

Special Considerations:
Interfering factors:

• high levels of vitamin C
• X-ray contrast agents

Drugs that can interfere with test results include alcohol, anti-inflammatory drugs (such as NSAIDs), salicylates, thiazide diuretics, and warfarin.


These spiked rods are uric acid crystals photographed under polarized light. Increased uric acid blood levels and formation of uric acid crystals in the joints are associated with gout.