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. It helps tell your doctor how well your kidneys are working. This test is done most often to check the kidneys in people with diabetes. Other conditions also cause albuminuria. These conditions include high blood pressure, heart failure, and cirrhosis.
The sooner your doctor knows you have kidney damage, the more your doctor can do to protect your kidneys.
How To Prepare
- Do not exercise just before the test.
- Tell your doctor if you are having your period or have vaginal discharge.
- Your doctor or the lab likely will give you the container you need to hold the urine. You will get instructions on when and how to collect the urine. This might be a one-time sample or a number of samples over a period of time.
How It Is Done
Random one-time test
A morning urine sample gives the best information about albumin levels.
- Wash your hands before you collect the urine.
- Prepare the container.
If the container has a lid, remove the lid and set it down with the inner surface up.
- Clean the area around your penis or vagina.
- Start to urinate into the toilet or urinal.
- Collect the urine in the container.
After the urine has flowed for several seconds, place the collection container in the stream. Collect about 2 ounces (a quarter cup) of this "midstream" urine without stopping the flow. Don't touch the rim of the container to your genital area.
- Finish urinating.
- Replace the lid on the container.
- Wash your hands.
Specific period of time test
You collect your urine for a period of time, such as over 4 or 24 hours. Your doctor will give you a large container that holds about 1 gallon. You will use the container to collect your urine.
- When you first get up, you empty your bladder.
But don't save this urine. Write down the time you began.
- For the set period of time, collect all your urine.
Each time you urinate during this time period, collect your urine in a small, clean container. Then pour the urine into the large container. Don't touch the inside of either container with your fingers.
- Don't get toilet paper, pubic hair, stool (feces), menstrual blood, or anything else in the urine sample.
- Keep the collected urine in the refrigerator for the collection time.
- Empty your bladder for the last time at or just before the end of the collection period.
Add this urine to the large container. Then write down the time.
How It Feels
This test usually doesn't cause any pain or discomfort.
There are no known risks from having this test.
Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn't in the normal range may still be normal for you.
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. 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.
Current as of: September 8, 2022
Author: Healthwise Staff
E. Gregory Thompson MD - Internal Medicine
Kathleen Romito MD - Family Medicine
Adam Husney MD - Family Medicine
Caroline S. Rhoads MD - Internal Medicine