[Skip to Content]

Urine Test: Microalbumin-to-Creatinine Ratio

Medically reviewed by: Larissa Hirsch, MD

What Is a Urine Test?

Testing a urine sample can help doctors find out what's going on when someone has an infection or other problem in kidneys, bladder, or other parts of the urinary tract.

To help your child get ready for a urine test, find out if they need to avoid any specific foods or activity before the test, or should stop taking any medicines.

Urine tests are painless. To help ease any fears, explain in simple terms how the test is done and why it's needed. Make sure your child understands that the urinary opening (urethra) must be cleaned as instructed and the pee must be collected midstream. Things like toilet paper or hair must not get in the sample.

What Is a Microalbumin-to-Creatinine Ratio Test?

Creatinine (kree-AT-eh-neen) is a waste product our muscles make at a steady rate during normal daily activity. The bloodstream carries creatinine to the kidneys, which filter it out of the blood. Then, creatinine passes out of the body in urine (pee). Albumin (al-BYOO-min) is a type of protein.

A microalbumin-to-creatinine ratio urine test measures how much albumin is in the pee and compares that with how much creatinine is in it.

Why Are Microalbumin-to-Creatinine Ratio Tests Done?

Normally, the body filters out creatinine in pee at a steady rate. Comparing the ratio of urine albumin with creatinine in the same urine sample helps doctors see if the body is excreting albumin at an increased rate. If it is, this might be a sign of kidney disease.

Healthy kidneys prevent albumin and other proteins from entering pee. But damaged kidneys start letting proteins pass from the blood into pee. 

Doctors may do a microalbumin-to-creatinine ratio test to:

  • screen for kidney problems in teens with diabetes
  • monitor kidney function in kids and teens already diagnosed with kidney disease or who take medicines that can affect the kidneys
  • detect kidney problems due to hypertension (high blood pressure) and autoimmune diseases

If the test results show signs of a problem, more urine tests may be done.

What if I Have Questions?

If you have questions about the microalbumin-to-creatinine ratio test, talk to your doctor. 

Medically reviewed by: Larissa Hirsch, MD
Date reviewed: March 2023