Urine Albumin-Creatinine Ratio (uACR)

What is the urine albumin-creatinine ratio?

The urine albumin-creatinine ratio (uACR) is a type of urine test (urinalysis) that measures how much albumin and creatinine are in your pee. The levels of these substances help provide healthcare providers information about your kidney health.

Albumin is a protein in your blood plasma. Your liver makes albumin, which keeps fluid from leaking out of your bloodstream, and circulates vitamins, enzymes and hormones throughout your body.

Creatinine is a creatine waste product. Your body uses creatine to provide energy to your skeletal muscles to help them flex (contract). When your muscles use energy, they break down and release creatinine into your bloodstream.

If your kidneys are healthy, they:

• Prevent albumin from entering your pee so it stays in your blood.
• Filter creatinine from your blood so it leaves your body when you pee.

If you have kidney damage, small amounts of albumin (microalbumin) can enter your pee (proteinuria), and creatinine may remain in your body.

When is a urine albumin-creatinine ratio performed?

A healthcare provider usually orders a urine albumin-creatinine ratio to check your kidney health if you have diabetes or chronic kidney disease (CKD). They may also order a uACR if you have:

• High blood pressure (hypertension)
• Heart disease
• Cirrhosis of the liver

In some cases, a provider may order uACR if you have a body mass index (BMI) greater than 30 (have obesity), smoke or are over 50.

How does a urine albumin-creatinine ratio test work?

There are different types of urine albumin-creatinine ratio tests:

• “Spot” pee sample. This is a one-time pee sample. Healthcare providers use your sample to measure exactly how much albumin and creatine are in your pee. You’ll provide your sample at a provider’s office or a lab.
• Early morning/timed pee sample. You collect your sample at home in a specimen cup when you wake up or after not peeing for at least four hours.
• 24-hour pee collection. A provider will give you a large specimen cup that you pee into every time you use the bathroom over 24 hours. In between using the bathroom, you keep the cup in a refrigerator. A 24-hour pee collection is the most accurate type of uACR. But providers typically only order it if your spot pee sample or early morning/timed pee sample results are abnormal.

What should I expect before a urine albumin-creatinine ratio test?

A healthcare provider will give you specific instructions to prepare you for a urine albumin-creatinine ratio test. In general:

• Make sure you drink enough fluids to provide enough pee for your sample.
• Avoid intense exercise for at least 24 hours before the test. Intense exercise may temporarily increase the amount of albumin in your pee.
• Avoid eating meat for at least 24 hours before the test. Eating meat may temporarily impact your creatinine levels.

Let a healthcare provider know if you:

• Are on your period (menstruating) or have bleeding hemorrhoids.
• Have a urinary tract infection (UTI), fever, gum infection (periodontitis) or viral hepatitis.

Blood or bacteria in your pee sample can also interfere with your results.

What should I expect during a urine albumin-creatinine ratio test?

The instructions may vary according to your healthcare provider or lab, but in general, a urine albumin-creatinine ratio test uses the “clean catch” method, which helps prevent contamination. A provider will give you a specimen cup and sterile wipes (wet wipes).

1. Wash your hands with antibacterial soap and water.
2. Clean your genital area with a sterile wipe.
3. Pee a small amount into the toilet.
4. Stop peeing.
5. Hold the specimen cup a few inches from your urethra.
6. Fill the specimen cup to about half full or to the line the provider instructed you to fill.
7. Stop peeing and put your specimen cup down.
8. Finish peeing in the toilet.
9. Put the cap on the specimen cup and return it to a provider.

What should I expect after a urine albumin-creatinine ratio test?

After a healthcare provider collects your pee sample, they’ll send it to a lab for testing.

What are the risks of a urine albumin-creatinine ratio test?

There aren’t any risks in collecting a pee sample, and the “clean catch” method is noninvasive and painless.

What type of results do you get and what do the results mean?

A urine albumin-creatinine ratio compares the amounts of albumin and creatinine in your pee to each other. The ratio is in milligrams to grams (mg/g). A lower uACR is better than a higher uACR.

What is a normal urine albumin-creatinine ratio?

A normal urine albumin-creatinine ratio is less than 30 mg/g. This usually indicates that you’re at a very low risk of kidney failure, heart attack or stroke. A healthcare provider may ask you to repeat a uACR a few months later to confirm your results.

You’re at a higher risk of kidney failure, heart failure or stroke if your uACR is between 30 and 299 mg/g. A provider may ask you to repeat a uACR a few months later. If it’s in the same range, you may have kidney disease.

What does it mean if my urine albumin-creatinine ratio is high?

If your urine albumin-creatinine ratio is slightly higher than expected, you may have mild kidney disease. A high uACR means you have moderate or severe kidney disease.

What level of urine albumin-creatinine indicates kidney failure?

If your uACR is 300 mg/g or higher and a provider confirms it during a repeat test, you may have kidney disease. You’re also at severe risk of kidney failure, heart attack or stroke.

When should I know the results of urine albumin-creatinine ratio?

In most cases, you should get your urine albumin-creatinine ratio results in a day or two.

If the results are abnormal, what are the next steps?

A healthcare provider will likely order additional urine albumin-creatinine ratio tests if your results are abnormal. They may also order other tests to help diagnose kidney disease, including:

• Estimated glomerular filtration rate (eGFR), which is part of a standard blood test
• Imaging tests, including an ultrasound
• Kidney biopsy

When should I call my doctor?

Reach out to a healthcare provider if you have any questions about your urine albumin-creatinine ratio test results. If necessary, schedule follow-up appointments for additional testing.

If you have kidney disease or your uACR results indicate a risk of kidney disease, call a provider if you experience:

• Changes to your peeing habits, including peeing more than usual, foamy pee or blood in your pee (hematuria)
• Dry or itchy skin, or darkening skin
• Fatigue
• Nausea and vomiting
• Swollen hands, feet or ankles (edema)