Microalbumin is a small amount of a protein called albumin. It is normally found in the blood. Creatinine is a normal waste product found in urine. A microalbumin creatinine ratio compares the amount of albumin to the amount of creatinine in your urine.
If there is any albumin in your urine, the amount can vary greatly throughout the day. But creatinine is released as a steady rate. Because of this, your health care provider can more accurately measure the amount of albumin by comparing it to the amount of creatinine in your urine. If albumin is found in your urine, it may mean you have a problem with your kidneys.
Other names: albumin-creatinine ratio; urine albumin; microalbumin, urine; ACR; UACR
A microalbumin creatinine ratio is most often used to screen people who are at higher risk for kidney disease. These include people with diabetes or high blood pressure. Identifying kidney disease at an early stage can help prevent serious complications.
You may need this test if you have diabetes. The American Diabetes Association recommends:
If you have high blood pressure, you may get a microalbumin creatinine ratio at regular intervals, as recommended by your health care provider.
For a microalbumin creatinine ratio you will be asked to provide either a 24-hour urine sample or a random urine sample.
For a 24-hour urine sample, you will need to collect all urine passed in a 24-hour period. Your health care provider or a laboratory professional will give you a container to collect your urine and instructions on how to collect and store your samples. A 24-hour urine sample test usually includes the following steps:
For a random urine sample, you will receive a container in which to collect the urine and special instructions to ensure the sample is sterile. These instructions are often referred to as the “clean catch method.” The clean catch method includes the following steps:
You don’t need any special preparations for a microalbumin creatinine ratio.
There is no known risk to a 24-hour urine sample or a random urine sample.
If your microalbumin creatinine ratio shows albumin in your urine, you may get tested again to confirm the results. If your results continue to show albumin in urine, it may mean you have early-stage kidney disease. If your test results show high levels of albumin, it may mean you have kidney failure. If you are diagnosed with kidney disease, your health care provider will take steps to treat the disease and/or prevent further complications.
If small amounts of albumin are found in your urine, it doesn’t necessarily mean you have kidney disease. Urinary tract infections and other factors can cause albumin to show up in urine. If you have questions about your results, talk to your health care provider.
Be sure not to confuse “prealbumin” with albumin. Although they sound similar, prealbumin is a different type of protein. A prealbumin test is used to diagnose different conditions than a microalbumin creatinine ratio.