Here is a number worth a second look. According to the CDC’s latest national estimate, updated in March 2026, about 1 in 3 adults 65 and older has chronic kidney disease.
And across all adults who have it, the CDC says about 9 in 10 don’t know.
That gap has a simple explanation. Kidney disease is quiet, and testing is the only way to know how well your kidneys are working. It takes two routine tests, and one of them gets skipped far more often than you might expect.
What Your Kidneys Do All Day
Your kidneys are two fist-sized organs tucked just below your rib cage. According to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), healthy kidneys filter about half a cup of blood every minute, pulling out waste and extra water to make urine. They also make hormones that help control your blood pressure, make red blood cells, and keep your bones strong.
Chronic kidney disease means the kidneys are damaged and can’t filter blood the way they should, so waste and extra fluid can build up.
Why It Stays Hidden
NIDDK says most people in the early stages have no symptoms, and many have none until the disease is advanced. Signs like swelling in the ankles, feeling tired, or a change in how often you urinate may show up as the disease progresses.
The CDC names diabetes and high blood pressure as the two biggest causes. NIDDK adds heart disease and a family history of kidney disease to the list of risk factors, and notes that the risk increases with age.
Two Tests, and the One That Gets Skipped
Two simple tests check your kidneys:
- A blood test that estimates your GFR (glomerular filtration rate), which shows how well your kidneys filter. A GFR of 60 or more is in the normal range.
- A urine test that checks for albumin, a protein that can leak into the urine when the kidneys are damaged. A result above 30 mg/g may be a sign of kidney disease.
The CDC puts it plainly: if your GFR is 60 or more together with a normal urine albumin test, you are in the normal range. It takes both results to get the full picture.
Yet the urine test often slips through the cracks. A study published in the journal Diabetes Care looked at lab records for more than 28 million American adults with diabetes, high blood pressure, or both, between 2013 and 2019. About 9 in 10 had the kidney blood test. Only about 1 in 5 had the urine test.
The newest blood pressure guideline, released in 2025 by the American Heart Association and the American College of Cardiology, now recommends the urine test for everyone with high blood pressure.
If you have diabetes, NIDDK recommends getting checked every year. If you have high blood pressure, heart disease, or a family history of kidney failure, ask your doctor how often you should be tested.
Medicare Part B covers medically necessary diagnostic lab tests when your doctor orders them, and you usually pay nothing.
What Your Numbers Mean for You
A single result is a starting point. NIDDK notes that doctors generally diagnose chronic kidney disease when test results showing kidney damage or reduced function last for more than three months, and a urine test may be repeated once or twice to confirm a result. The CDC also notes that its national estimate rests on a single round of tests, so the true figure might be lower.
Age matters too. In guidance for doctors, NIDDK explains that kidney function tends to decrease with age, though this hasn’t been well studied, and that many people with this kind of age-related change may not progress to kidney failure. Its own example: the outlook for a 75-year-old with a GFR of 55 may be different than for a 45-year-old with the same number.
Keeping Your Kidneys Steady
NIDDK says advanced kidney disease typically can’t be reversed. The sooner you find it, the sooner you can protect your kidneys from further damage. Here is what helps:
- Keep your blood pressure at the goal your doctor sets. NIDDK calls blood pressure control the most important step in treating kidney disease.
- If you have diabetes, keep your blood sugar close to your goal.
- Be careful with everyday pain relievers. NIDDK warns that regular use of NSAIDs such as ibuprofen and naproxen can damage the kidneys. If you take them often, ask your doctor about other options, and never stop a prescribed medicine on your own.
- Ask about kidney-protecting medicines. NIDDK says two types of blood pressure medicines, ACE inhibitors and ARBs (their names end in -pril or -sartan), may slow kidney disease, even in people who don’t have high blood pressure.
- Cut back on salt, stay active, and if you smoke, stop.
Medicare Part B also covers medical nutrition therapy with a registered dietitian for people with diabetes or certain stages of kidney disease, or a kidney transplant in the last 36 months, with a doctor’s referral. You pay nothing if you qualify.
The Bottom Line
About a third of people our age may have kidney disease, and most who have it don’t know. The blood test is common. The urine test is the one that often gets missed, and it takes both to know where you stand.
Ask for both. Ask what your numbers mean for you. And keep track of them over time. Always listen to what your doctor says and don’t change your medication or start taking new ones unless your doctor says so.