Lifestyle

The Simple Urine Test That Can Catch Kidney Damage Early, and Why Many Checkups Leave It Out

By Mike Harper · November 3, 2026

Routine blood work often includes a check of how well the kidneys filter. The test that shows whether they are already leaking protein is a separate urine test, and many patients never get it.

It is called the urine albumin-creatinine ratio, or uACR. The National Kidney Foundation says healthy kidneys stop most albumin, a protein in the blood, from getting into the urine. When the kidneys are damaged, albumin can leak through. The foundation says albumin in the urine can be a sign of kidney disease even when the blood test result, called eGFR, is above 60, or “normal.”

Why it matters. Kidney disease often goes unnoticed. The Centers for Disease Control and Prevention estimates that more than 1 in 10 U.S. adults, about 37 million people, have chronic kidney disease, and that about 9 in 10 adults with it don’t know they have it. The CDC puts the rate at 34% among people 65 and older. The agency notes its estimates rely on a single test result and might overstate the number. The NKF says kidney disease usually does not cause symptoms until its later stages, and that albumin in the urine raises the risk of kidney failure, heart attack and stroke.

Why checkups leave it out. In an August 2026 analysis of Medicare claims, the NKF and Manatt Health found that eGFR blood testing was common, at about 80% or higher in most years, while uACR testing continued to lag. In 2023, only 20% of people in Traditional Medicare and 28% of those in Medicare Advantage got both tests. The foundation has also said that fewer than half of people with diabetes and fewer than 15% of people with high blood pressure get the recommended uACR each year.

It is not the usual dipstick. Many checkups include a routine urinalysis, where a strip dipped in urine changes color. The NKF says the quantitative uACR is different. It measures the actual amounts of albumin and creatinine in a single “spot” urine sample and reports a number.

Who should ask. The NKF recommends a uACR at least once a year for anyone with diabetes, high blood pressure, heart disease or a history of heart attack or stroke, heart failure, a family history of kidney disease, a body mass index over 30, smoking or other tobacco use, or anyone over age 60.

Reading the result. Look for the line on the lab report with the word “ratio.” The NKF calls a result lower than 30 mg/g normal. A result from 30 to 299 is moderately increased, and 300 or higher is severely increased. The National Institute of Diabetes and Digestive and Kidney Diseases says more than 30 mg/g may be a sign of kidney disease and that a provider may repeat the test one or two more times to confirm. The NKF says a confirmed high result twice in six months may mean kidney disease.

Getting an accurate reading. The NKF suggests avoiding intense exercise for 24 hours before the test, since it can raise the number temporarily. A fever, infection, urinary tract infection or a sudden spike in blood pressure or blood sugar can also cause a false positive.

The NKF offers a simple question to bring to your next visit: when was the last time I had a uACR test? If the answer is never, ask whether you should have a urine albumin-creatinine ratio, rather than only a dipstick.

This article is for general information and is not medical advice. Talk with your doctor about which kidney tests are right for you. This article was produced with the assistance of AI and fact-checked against the sources cited by LightWave Reports.