Albumin Urine Test
An albumin test checks urine for a protein called albumin. Albumin is normally found in the blood and filtered by the kidneys. When the kidneys are working as they should, there may be a very small amount of albumin in the urine. But when the kidneys are damaged, abnormal amounts of albumin leak into the urine. This is called albuminuria. If the amount of albumin is very small, but still abnormal, it is called microalbuminuria.
If early kidney damage is not treated, larger amounts of albumin may leak into the urine. When the kidneys spill albumin, it can mean serious kidney damage is present. This can lead to chronic kidney disease.
An albumin urine test can be done on a sample of urine that is collected:
- At a random time. This is usually after the first time you urinate in the morning.
- Over a 24-hour period.
- Over a specific period of time, such as 4 hours or overnight.
Why It Is Done
This test is done to check for albumin in the urine. Finding it early may change treatment so a person will keep as much kidney function as possible.
Sometimes an albumin-creatinine ratio test is also done. This urine test compares the amount of albumin with the amount of a waste product called creatinine (say "kree-AT-uh-neen"). The test can help give a more accurate measure of albumin levels. This is because the amount of albumin can change, depending on how much water is in your urine. But creatinine levels tend to stay the same.
How It Is Done
For a random urine test, you will provide a clean-catch midstream urine sample. A morning urine sample gives the best information about albumin levels.
Clean-catch midstream one-time urine collection
- Wash your hands to make sure they are clean before you collect the urine.
- If the collection cup has a lid, remove it carefully. Set it down with the inner surface up. Do not touch the inside of the cup with your fingers.
- Clean the area around your genitals.
- For men: Pull back the foreskin, if you have one. Clean the head of the penis thoroughly with medicated towelettes or swabs.
- For women: Spread open the folds of skin around the vagina with one hand. Then use your other hand to clean the area around the vagina and urethra thoroughly with medicated towelettes or swabs. Wipe the area from front to back to avoid spreading bacteria from the anus to the urethra.
- Start urinating into the toilet or urinal. Women should keep holding apart the folds of skin around the vagina while they urinate.
- After the urine has flowed for several seconds, place the collection cup into the stream. Collect about2 fl oz (60 mL) of this "midstream" urine without stopping the flow.
- Do not touch the rim of the cup to your genital area. And don't get toilet paper, pubic hair, stool (feces), menstrual blood, or other foreign matter in the urine sample.
- Finish urinating into the toilet or urinal.
- Carefully replace the lid on the cup. Return the cup to the lab. If you are collecting the urine at home and can't get it to the lab in an hour, refrigerate it.
A urine sample collected over time, such as over 4 or 24 hours, gives the most accurate results. So you may be asked to collect your urine over a specific time period.
Timed urine collection (24 hours)
- You start collecting your urine in the morning. When you first get up, empty your bladder but do not save this urine. Write down the time that you urinated. This marks the beginning of your 24-hour collection period.
- For the next 24 hours, collect all your urine. Your doctor or lab will usually provide you with a large container that holds about1 gal (4 L). The container has a small amount of preservative in it. Urinate into a small, clean container, and then pour the urine into the large container. Do not touch the inside of either container with your fingers.
- Keep the large container in the refrigerator for the 24 hours.
- Empty your bladder for the final time at or just before the end of the 24-hour period. Add this urine to the large container, and record the time.
- Do not get toilet paper, pubic hair, stool (feces), menstrual blood, or other foreign matter in the urine sample.
An albumin test checks urine for the presence of a protein called albumin. This is called albuminuria. It is most often caused by kidney damage from diabetes. But many other conditions can lead to kidney damage.
These numbers are just a guide. The range for "normal" varies from lab to lab. Your lab may have a different range. Your lab report should show what range your lab uses for "normal." Also, your doctor will evaluate your results based on your health and other factors. So a number that is outside the normal range here may still be normal for you.
One-time collection (spot urine collection):
Adults moving around: Less than 150 mg in 24 hours or less than 0.15 g per day footnote 2
10-hour (overnight) collection:
You may need more than one test to find out how well your kidneys are working.
- If your results are higher than normal, your doctor may check your urine more often to watch for kidney damage.
- If you have 2 or 3 high results in a 3- to 6-month period and you have diabetes, your doctor may find kidney damage (diabetic nephropathy). Even though diabetes is the most common reason for high results, there are many other kidney problems that can cause high results.
Pregnant women with diabetes may have their urine checked to watch for high amounts of albumin.
What Affects the Test
You may not be able to have the test, or the results may not be helpful, if:
- You have a urinary tract infection, high blood pressure, heart failure, or a high fever during an infection.
- You exercise just before the test.
- You take medicines such as aspirin, corticosteroids, or some antibiotics, such as amoxicillin.
- You have menstrual bleeding or vaginal discharge. These may temporarily affect the urine sample.
What To Think About
- The American Diabetes Association recommends three tests to check for kidney damage. These tests are blood pressure, urine albumin, and a creatinine blood test to calculate an estimated glomerular filtration rate (eGFR). Creatinine is a waste product that is filtered out of the blood by healthy kidneys. To learn more, see the topic Creatinine and Creatinine Clearance.
- If you have type 2 diabetes, you should have these tests when you are first diagnosed. Then have them each year to check for diabetic nephropathy.
- If you have type 1 diabetes, you should have these tests to check for diabetic nephropathy each year, starting 5 years after diagnosis.
- If you have either type of diabetes and are pregnant, talk to your doctor about how often you need to be tested.
- The urine dipstick test can be used to check for albumin in a single sample of urine. But the dipstick test is not as accurate a test for finding albuminuria as the urine test. It is not recommended in place of an albumin urine test.
- Pagana KD, Pagana TJ (2010). Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
- Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
- Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Current as of: October 31, 2018