Kidney disease may go unnoticed: signs worth watching for

Kidney disease can progress without clear symptoms, which makes routine testing more valuable than waiting for a warning sign. That is especially true for older adults and for people with diabetes or high blood pressure, who may already have kidney damage before they feel unwell.

The kidneys remove waste and excess fluid from the blood while helping keep the body’s chemical balance stable. When kidney function starts to decline, the effects can build slowly and eventually influence energy, fluid levels and other parts of health, sometimes becoming apparent only after significant damage has already occurred.

Blood and urine tests can identify problems that symptoms may miss. Detecting kidney disease earlier gives a healthcare professional a chance to look for the cause and discuss steps that may help preserve remaining kidney function.

According to guidance from the National Institute of Diabetes and Digestive and Kidney Diseases, early chronic kidney disease often causes no symptoms at all. Feeling fine therefore does not rule it out, and risk factors matter more than a simple symptom checklist when deciding whether testing is needed.

Swelling in the ankles or feet can happen when the body holds on to extra fluid. However, swelling can have many causes, including ones unrelated to the kidneys, so its meaning depends on a person’s medical history and a clinical evaluation.

Changes in urine may also be important. Urine that stays foamy could suggest protein is leaking into it, while urinating more often, especially during the night, can occur with kidney problems as well as other common conditions.

For a fuller explanation, see warning signs associated with kidney failure.

Blood in the urine should be evaluated rather than automatically blamed on kidney disease. Infections, stones and other urinary tract conditions can also cause this symptom, and finding the cause is more useful than trying to judge it by appearance alone.

More advanced kidney disease can lead to fatigue, loss of appetite, nausea, itching or trouble concentrating. These symptoms are not unique to the kidneys, but ongoing or unexplained changes should be discussed with a clinician rather than written off as normal aging.

Testing typically includes a blood test to estimate how well the kidneys are filtering and a urine test for albumin, a protein that may leak through damaged filters. Because these tests provide different information, a normal result on one does not necessarily answer the whole question.

An abnormal result may need to be repeated and followed up before its meaning is clear. A clinician looks at the pattern over time, along with other illnesses and medications, instead of diagnosing chronic kidney disease from one symptom or a single reading.

For people at risk, discussing a suitable testing plan is a practical step even when no symptoms are present. Managing blood pressure and diabetes, reviewing medications and avoiding treatments that may harm the kidneys can all be part of an individual plan; advice about fluids and diet should be tailored to the person’s needs.

If you are interested in this topic, please read articles about Nutrition and chronic kidney disease: a guide to eating well, and Ultra-processed foods may increase risk of chronic kidney disease.

For more information, please see articles about Eating smart for kidney health: High-potassium foods to avoid, and Eating nuts linked to lower risk of chronic kidney disease, death.

Source: National Institute of Diabetes and Digestive and Kidney Diseases; National Kidney Foundation.