Chronic Kidney Disease After 50: Why 9 in 10 People With It Don’t Know, and the Simple Tests That Find It

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Quick answer: Chronic kidney disease (CKD), a gradual loss of the kidneys’ ability to filter blood, affects about 34% of U.S. adults 65 and older, compared with 12% of those aged 45 to 64, and as many as 9 in 10 people with it don’t know. Early CKD typically causes no symptoms, so it’s found through two simple tests: a blood test (creatinine, used to calculate eGFR) and a urine test for albumin. The two biggest causes are diabetes and high blood pressure. Kidney damage generally can’t be reversed, but catching it early and controlling blood pressure and blood sugar can slow it substantially, and newer medications have meaningfully improved the outlook.

What the kidneys do, and what chronic kidney disease means

The kidneys filter waste and excess fluid from the blood, balance minerals like sodium and potassium, help regulate blood pressure, make a hormone that supports red blood cell production, and activate vitamin D. Chronic kidney disease means these functions have been reduced for at least three months, usually because the tiny filtering units inside the kidneys have been gradually damaged. Because the kidneys have a large functional reserve, a person can lose a substantial share of kidney function before feeling anything unusual, which is why this is among the most underdiagnosed major conditions: the damage accumulates quietly for years.

Why it becomes so much more common with age

Kidney filtering capacity naturally declines with age, so older adults have less reserve to begin with, and decades of exposure to the main drivers of kidney damage, high blood pressure and high blood sugar, accumulate. The prevalence climbs from about 6% in adults 18 to 44, to 12% at 45 to 64, to 34% at 65 and older, and is highest in people 70 and over. Heart disease, obesity, and a family history of kidney disease raise risk further, as does long-term use of certain medications, particularly regular, frequent use of nonsteroidal anti-inflammatory drugs such as ibuprofen and naproxen, which is an especially relevant point for people managing joint pain, discussed in our joint pain guides.

The two simple tests that detect it

Kidney disease is found with two routine tests, and both are inexpensive. The first is a blood test measuring creatinine, a waste product filtered by the kidneys, which is used with age and sex to calculate the eGFR (estimated glomerular filtration rate), the standard measure of kidney function. The second is a urine test for albumin, a protein that leaks into the urine when the kidney’s filters are damaged, and it often becomes abnormal before eGFR changes, which makes it an important early signal. Using both tests together is more informative than either alone, and it’s a reason to confirm that a routine checkup includes them, especially for anyone with diabetes, high blood pressure, or heart disease, for whom regular testing is specifically recommended.

Symptoms that appear later

When kidney function has fallen significantly, symptoms can include fatigue, swelling in the ankles, feet, or around the eyes, changes in urination, such as more frequent urination at night or foamy urine, itchy skin, nausea, poor appetite, muscle cramps, and difficulty concentrating. These are nonspecific and overlap with many other conditions, and by the time they appear, kidney disease is usually advanced, which is the central reason testing is recommended before symptoms, not in response to them.

What slows progression

The most effective step is controlling the underlying causes. For high blood pressure, treatment targets are often tighter in people with kidney disease, and certain blood pressure medications, ACE inhibitors and ARBs, offer kidney-protective benefits beyond lowering pressure, particularly when albumin is present in the urine. For diabetes, keeping blood sugar well controlled reduces ongoing kidney damage, and a newer class of diabetes medications, SGLT2 inhibitors, has been shown in large trials to slow kidney disease progression and reduce heart risk, including in people with CKD who don’t have diabetes, though the measured benefit in non-diabetic patients was smaller than in those with diabetes, and one of these drugs received FDA approval in 2023 for adults with CKD at risk of progression regardless of diabetes status, which is a significant development worth asking a doctor about. Avoiding regular use of NSAIDs, staying hydrated, not smoking, and keeping a healthy weight all help. People with advanced kidney disease may also need dietary adjustments, such as limiting sodium and, in later stages, potassium and phosphorus, which should be guided by a doctor or dietitian rather than self-directed.

Who should specifically ask for testing

Anyone with diabetes, high blood pressure, heart disease, or a family history of kidney failure should have kidney testing at least yearly, and so should people over 60 who haven’t had kidney function checked recently. If you take pain relievers like ibuprofen or naproxen regularly, mention it to your doctor, because dosing and duration matter for kidney safety. If your last routine labs included a basic metabolic panel, your creatinine was probably measured, but the urine albumin test is a separate test that is often not included unless requested.

Understanding the stages and what your eGFR number means

CKD is divided into five stages based mainly on eGFR, measured in milliliters per minute. Stage 1 and 2 describe eGFR of 90 or above and 60 to 89 respectively, and in these stages a diagnosis requires other evidence of kidney damage, such as albumin in the urine, since a mildly reduced eGFR alone can be a normal finding with age. Stage 3 is split into 3a, with eGFR 45 to 59, and 3b, with eGFR 30 to 44. Stage 4 is 15 to 29, and stage 5, below 15, is kidney failure, the point at which dialysis or a transplant becomes a consideration. Most older adults with CKD are in stage 3, and many remain there for years without progressing to advanced disease, particularly with good blood pressure and blood sugar control, which is why a diagnosis, especially at stage 3, is better understood as a call for monitoring and protection than as an inevitable path to dialysis. Doctors also look at the albumin level, because the combination of the two numbers, not eGFR alone, determines how closely the disease needs to be watched.

Everyday habits that protect your kidneys

Several routine choices have a direct effect on kidney health. Staying adequately hydrated supports kidney function, though there’s no benefit to drinking excessive amounts of water, and people with advanced kidney disease or heart failure may be given specific fluid limits by a doctor. Limiting sodium reduces blood pressure and the strain on the kidneys, and it also enhances the effect of some blood pressure medications. Being cautious with over-the-counter pain relievers and with supplements is worth emphasizing: certain herbal products and high-dose supplements can be harmful to kidneys, so it’s sensible to tell the doctor and pharmacist everything you take. Regular physical activity and maintaining a healthy weight lower the risk of the diabetes and high blood pressure that drive most kidney disease, which makes the habits covered across this site’s heart and metabolic guides directly relevant here too.

Because the tests are simple and the early disease is silent, the most practical step for anyone over 60, or anyone with diabetes, high blood pressure, or heart disease, is to confirm that both a kidney function blood test and a urine albumin test have been done recently, and to ask about the results by number rather than just “normal.”

Related guides

• Prediabetes After 50: What the Numbers Mean and Why 80% of People Don’t Know They Have It
• Glaucoma After 50: The Silent Eye Disease Half of Patients Don’t Know They Have
• Why afternoon naps don’t fix your midday slump
• Underactive Thyroid After 50: The Common Condition Often Mistaken for Normal Aging

Frequently asked questions

Can kidney damage be reversed?

Generally no. Damage to the kidney’s filters is usually permanent, but treatment can slow or sometimes stabilize progression, and some forms caused by acute, reversible problems can improve.

How would I know if I have kidney disease?

Usually not from symptoms, since early CKD rarely causes any. It’s detected by a blood test (creatinine and eGFR) and a urine albumin test, which is why routine testing is recommended for people at higher risk.

Is occasional ibuprofen harmful to my kidneys?

Occasional use is generally low risk for people with healthy kidneys, but regular, frequent, or high-dose NSAID use can damage the kidneys, and people with existing kidney disease, or who are dehydrated or older, face higher risk. Discuss regular use with a doctor.