Urinalysis, 24-hour urinalysis
This test looks for uric acid in your urine. Your liver creates uric acid when it breaks down substances called purines. These are found in higher levels in foods like dried beans and peas, some types of fish, and liver. Some people may get rid of more uric acid in their urine. These include people who:
Eat foods high in purines
Have a type of arthritis called gout
Have certain types of leukemia
Are undergoing chemotherapy or radiation for certain cancers
Uric acid can also accumulate in the kidney as a type of kidney stone. Kidney stones can be painful to eliminate when urinating.
You may need this test if your health care provider suspects that you have gout. He or she may also use this test to monitor you while you have cancer treatment, or to check your urine after you have a kidney stone.
Your doctor may also test the pH, or acidity, of your urine and check for a substance called creatinine.
Many things may affect your lab test results. These include the method each lab uses to do the test. Even if your test results are different from the normal value, you may not have a problem. To learn what the results mean for you, talk with your health care provider.
Adults normally lose about 500 to 600 milligrams (mg) of uric acid in their urine every 24 hours. If you're eating a normal diet, losing more than 800 mg a day is considered too much.
If you eat lots of animal protein or purines, you may have more uric acid in your urine. A number of health problems can also cause you to make more uric acid, including gout, leukemia, obesity, cancer treatment, ileostomy, glycogen storage diseases, and Lesch-Nyhan syndrome.
This test requires a urine sample. Your health care provider may measure your uric acid levels using a 24-hour urine specimen. First, you will empty your bladder completely in the morning without collecting it and note the time. Then, you'll collect your urine every time you go to the bathroom over the next 24 hours.
This test poses no known risks.
Drinking alcohol or eating a lot of foods high in purines can affect the level of uric acid in your urine. If you are dehydrated, your level may appear high. Certain medications may also affect your test results. Ask your health care provider whether you should avoid any foods, beverages, medications, or other substances before having this test.
Be sure your doctor knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.