A urine microalbumin test is a test to detect very small levels of a blood protein (albumin) in your urine. A microalbumin test is used to detect early signs of kidney damage in people who are at risk of developing kidney disease.

Healthy kidneys filter waste from your blood and hang on to the healthy components, including proteins such as albumin. Kidney damage can cause proteins to leak through your kidneys and exit your body in your urine. Albumin (al-BYOO-min) is one of the first proteins to leak when kidneys become damaged.

Microalbumin tests are recommended for people with an increased risk of kidney disease, such as those with diabetes or high blood pressure.

Your doctor may recommend a urine microalbumin test to detect early signs of kidney damage. Treatment may prevent or delay more-advanced kidney disease.

How often you need microalbumin tests depends on any underlying conditions and your risk of kidney damage. For example:

• Type 1 diabetes. If you have type 1 diabetes, your doctor may recommend a microalbumin test once a year beginning five years after your diagnosis.
• Type 2 diabetes. If you have type 2 diabetes, your doctor may recommend a microalbumin test once a year beginning immediately after your diagnosis.
• High blood pressure. If you have high blood pressure, your doctor may recommend microalbumin tests more regularly. Discuss with your doctor how often to repeat this test.

If your urinary microalbumin level is elevated, your doctor may recommend treatment and more-frequent testing.

The microalbumin test is a simple urine test. You can eat and drink normally before the test. The amount of urine your doctor may want to test may vary — you may only need to provide a random sample, or your doctor may ask you to collect 24 hours' worth of urine.

During the microalbumin test, you simply need to provide a fresh urine sample. This may be done in several ways:

• 24-hour urine test. Your doctor may ask you to collect all of your urine in a special container over a 24-hour period and submit it for analysis.
• Timed urine test. Your doctor may ask you to provide a urine sample first thing in the morning or after a four-hour period of not urinating.
• Random urine test. A random urine test can be taken at any time. But to improve accuracy of the results, it's often combined with a urine test for creatinine — a waste product usually filtered by the kidneys.

The urine sample is sent to a lab for analysis. After you provide the urine sample, you can return to your usual activities immediately.

Results of the microalbumin test are measured as milligrams (mg) of protein leakage over 24 hours. Generally:

• Less than 30 mg is normal
• Thirty to 300 mg may indicate early kidney disease (microalbuminuria)
• More than 300 mg indicates more-advanced kidney disease (macroalbuminuria)

Discuss your test result with your doctor and find out what it means for your health. If your urinary microalbumin level is higher than normal, your doctor may recommend repeating the test.

Several factors can cause higher than expected urinary microalbumin results, such as:

• Blood in your urine (hematuria)
• Certain medications
• Fever
• Recent vigorous exercise
• Urinary tract infection
• Other kidney diseases