Early signs of kidney disease are almost always invisible. About 1 in 7 American adults, roughly 35 million people, have chronic kidney disease, and about 9 in 10 of them do not know it, according to the CDC. Kidneys can lose much of their function before causing symptoms. The good news is that two inexpensive tests can catch problems early, when lifestyle changes and treatment can slow or stop progression.
Quick Answer
- Chronic kidney disease affects about 1 in 7 U.S. adults, and about 9 in 10 don’t know it.
- Early kidney disease usually causes no symptoms.
- Two simple tests, a blood test (eGFR) and a urine test (albumin), catch it early.
- Diabetes and high blood pressure are the two leading causes.
What Do Your Kidneys Do?
Your kidneys filter about 200 quarts of blood every day, removing waste and extra fluid. They also help control blood pressure, balance minerals like sodium and potassium, keep bones healthy, and signal the body to make red blood cells. When kidneys are damaged, these jobs slowly suffer.
What Are the Early Signs of Kidney Disease?
In the early stages, most people feel completely normal. When symptoms do appear, kidney function has often declined significantly. Possible signs include:
- Swelling in the ankles, feet or around the eyes
- Foamy or bubbly urine, which can signal protein leaking
- Needing to urinate more often, especially at night
- Fatigue, trouble concentrating, or poor appetite
- Dry, itchy skin or muscle cramps
None of these signs is specific to kidney disease, which is why testing matters more than symptoms.
Which Tests Detect Kidney Disease Early?
International guidelines recommend two tests to identify and stage chronic kidney disease (KDIGO, Kidney Int, 2024):
- eGFR (estimated glomerular filtration rate): calculated from a blood creatinine test. An eGFR below 60 for three months or more suggests chronic kidney disease.
- uACR (urine albumin-to-creatinine ratio): a urine test that detects protein leaking into the urine. A result of 30 mg/g or higher is a sign of kidney damage, even when eGFR is normal.
Both measures predict future risk. A large analysis of over 1 million people found that lower eGFR and higher urine albumin were each independently linked with higher risk of death and cardiovascular death (CKD Prognosis Consortium, Lancet, 2010). Many standard panels include creatinine, but the urine albumin test is often skipped unless you ask. Our guide to lab numbers worth discussing with a clinician can help.
What Causes Chronic Kidney Disease?
Diabetes and high blood pressure are the two biggest causes, together accounting for most cases. Globally, chronic kidney disease affects more than 10% of adults, over 800 million people, and it has become one of the leading causes of death worldwide (Kovesdy, Kidney Int Suppl, 2022). Other risk factors include heart disease, obesity, smoking, family history, older age, and long-term use of certain pain medicines.
Because blood sugar is so central, our guide to prediabetes symptoms is a good companion read.
What Are Researchers Exploring Next?
Experts still debate whether everyone should be screened or only higher-risk groups. eGFR equations have limitations, especially at the extremes of muscle mass. A single abnormal result also needs to be repeated before a diagnosis is made.
5 Ways to Protect Your Kidneys
- Know your numbers. Ask for both an eGFR and a urine albumin test, especially if you have risk factors.
- Control blood pressure. Most guidelines aim for below about 130/80 for people with kidney disease.
- Manage blood sugar. Good glucose control protects the tiny filters in the kidneys.
- Use pain relievers carefully. Frequent use of NSAIDs like ibuprofen can harm kidneys; ask your clinician what is safe.
- Move, eat whole foods, and don’t smoke. These support kidneys, heart and blood vessels together. Heart and kidney health are closely linked, as our ApoB test guide explains.
Want to see which of your body’s systems needs attention first? Try the free Signal Map quiz.
Frequently Asked Questions
What are the first signs of kidney disease?
Early chronic kidney disease usually causes no symptoms. Later signs can include swelling in the ankles or feet, fatigue, foamy urine, changes in how often you urinate, and itchy skin. Because early disease is silent, blood and urine tests are the only reliable way to catch it.
Which tests check kidney function?
Two simple tests: a blood test for creatinine, used to estimate glomerular filtration rate (eGFR), and a urine test for albumin, often reported as the urine albumin-to-creatinine ratio (uACR). Using both gives the clearest picture.
Who should get tested for kidney disease?
People with diabetes, high blood pressure, heart disease, obesity, a family history of kidney failure, or who are over 60 are at higher risk and should ask their clinician about regular kidney testing.
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Sources
- Centers for Disease Control and Prevention. Chronic Kidney Disease in the United States, 2023. cdc.gov
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney Int. 2024;105(4S):S117-S314. doi:10.1016/j.kint.2023.10.018
- Chronic Kidney Disease Prognosis Consortium. Association of estimated glomerular filtration rate and albuminuria with all-cause and cardiovascular mortality in general population cohorts: a collaborative meta-analysis. Lancet. 2010;375(9731):2073-2081. doi:10.1016/S0140-6736(10)60674-5
- Kovesdy CP. Epidemiology of chronic kidney disease: an update 2022. Kidney Int Suppl. 2022;12(1):7-11. doi:10.1016/j.kisu.2021.11.003
This article is for education only and is not medical advice. Talk with your healthcare professional before changing your health routine.