What Is the Urine Albumin-to-Creatinine Ratio (UACR) Test?

The Urine Albumin-to-Creatinine Ratio (UACR) test is a test that checks to see if there is a protein called albumin in your urine. If there is albumin in your urine, this may be a sign that there is a problem with your kidneys.^1,2

What is albumin and creatinine?

Albumin is a type of protein in your blood. The job of your kidneys is to filter waste from your blood. After your blood is filtered, the waste leaves your body in your urine.¹

In healthy kidneys, there are filters that prevent albumin from leaving your body in your urine. When your kidneys are damaged, albumin may pass through those filters and leave through your urine.¹

The waste that is filtered can include creatinine. Creatinine is a waste product of creatine. It comes from the normal wear and tear of your muscles.¹

Why do doctors order a UACR test?

The UACR test compares the amount of albumin with the amount of creatinine in your urine. This can help doctors see how much albumin is in your urine.

Your doctor may order this test if they think you may have kidney disease. If you have been diagnosed with kidney disease, they may order it to monitor your condition or the progress of your treatment.^2,3

How can you prepare for the test?

Your doctor will provide you with any instructions for preparing for the UACR test. Ask your doctor if any of the medicines or supplements you take could affect your results.¹

You may need to avoid doing intense exercise and eating meat before the test. This is because intense exercise may affect the amount of albumin in your urine. And eating meat may affect the amount of creatinine in your urine.¹

What should you expect during the UACR test?

There are a few different kinds of UACR test. Your doctor will determine which test you will need. These are the different tests they may order:¹

• “Spot” urine test (also called a “random” urine test): This test is completed at a lab or office at any time during the day. You will provide a sample of your urine to be tested.
• Timed urine test: This test is done early in the morning after you have not gone to the bathroom in 4 hours. This test can be done at home.
• 24-hour urine test: This test is completed at your home over the course of 24 hours. You will pick up a container from your doctor or a lab. You will then collect all of the urine you produce in 24 hours in that container.

What do UACR test results mean?

Your doctor may order a UACR test for different reasons. This means that your results can mean different things.¹

For people who are not already diagnosed with kidney disease

If your doctor thinks you have kidney disease, they will test your UACR. Your UACR should be below 30 milligrams per gram (mg/g). If your UACR is above 30 mg/g, this means it is abnormal.²

A high UACR can be caused by something other than kidney disease including:¹

• Certain medicines
• Exercise
• Fever
• Inflammation
• Other health conditions

If you have a high UACR, your doctor will likely repeat the UACR test. If you have 2 UACR tests that are high over the course of 3 months or more, you may have kidney disease.²

For people who are diagnosed with kidney disease

If you are already diagnosed with kidney disease, you doctor may order a UACR to monitor your condition. If your UACR increases over time, this means your kidney disease is more severe. You may be more at risk for developing complications including problems with your heart and blood vessels.¹

To determine the severity of your kidney disease, here is a general range of UACR levels:²

• Normal UACR level: Less than 30 mg/g
• Moderate UACR level: 30-299 mg/g
• Severe UACR level: More than 300 mg/g

Keep in mind that your UACR may be affected by your diet, age, and muscle mass. Talk to your doctor about what your specific UACR results mean.¹