Learn 10 possible warning signs of kidney disease, including swelling, foamy urine, changes in urination, fatigue, itching, nausea, and shortness of breath—and when kidney testing may be needed.

Your kidneys work quietly every day to filter waste and extra fluid from your blood. They also help maintain the body’s fluid and mineral balance and contribute to blood-pressure regulation and red-blood-cell production.

The tricky part is that kidney disease can develop without obvious symptoms. In many people, noticeable symptoms appear only after kidney function has already declined significantly. That is why unusual changes in your body should not be ignored, particularly if you have diabetes, high blood pressure, heart disease, or a family history of kidney disease.

Here are 10 signs that can occur when kidney function is impaired.

1. Swelling Around the Feet, Ankles, or Legs

One of the noticeable signs of reduced kidney function can be swelling, also called edema.

When damaged kidneys have difficulty removing enough sodium and extra fluid, fluid can accumulate in the body. Swelling may appear around the ankles, feet, legs, hands, or sometimes the face and area around the eyes.

Persistent or unexplained swelling deserves medical attention, especially when it occurs together with urinary changes or fatigue.

2. Foamy or Very Bubbly Urine

Occasionally seeing bubbles in urine is not necessarily a sign of kidney disease. However, urine that repeatedly appears unusually foamy can sometimes be associated with excess protein in the urine.

Proteinuria can occur when the kidney’s filtering structures become damaged and allow proteins to pass into urine.

A urine test can determine whether protein is actually present rather than relying on appearance alone.

3. Changes in How Often You Urinate

Changes in urination can occur with advanced kidney disease.

You might notice that you are urinating much more or much less frequently than usual, including needing to urinate more often during the night.

However, urinary changes have many possible causes, including infections, diabetes, medications, pregnancy, and changes in fluid intake. They do not automatically mean that the kidneys are failing.

4. Persistent Tiredness or Weakness

Feeling unusually tired can occur when kidney disease becomes advanced.

Reduced kidney function can contribute to anemia and the buildup of waste products in the bloodstream. These changes can leave a person feeling weak, tired, or lacking energy.

Because fatigue is extremely common and has many causes, it should be considered alongside other symptoms and medical test results.

5. Nausea or Loss of Appetite

As kidney function becomes severely reduced, waste products can accumulate in the blood.

This can contribute to nausea, vomiting, reduced appetite, and sometimes unintended weight loss.

These symptoms can also be caused by many digestive and other medical conditions, so they should not be used alone to diagnose kidney disease.

6. Persistent Itching or Very Dry Skin

Persistent itching can occur in advanced kidney disease.

When kidney function is severely impaired, changes in mineral balance and the accumulation of waste products can contribute to itchy or dry skin.

Unexplained, persistent itching—particularly when accompanied by swelling, fatigue, or changes in urination—should be discussed with a healthcare professional.

7. Muscle Cramps

Muscle cramps can occur in people with advanced kidney disease.

Kidneys help maintain the body’s balance of minerals and electrolytes. When kidney function declines significantly, these balances can become disturbed.

Nighttime or recurring cramps have many other possible causes, however, so they are not proof of kidney disease by themselves.

8. Difficulty Concentrating or Trouble Sleeping

Advanced kidney disease can affect how a person feels mentally and physically.

Some people experience difficulty concentrating, sleep problems, drowsiness, or a general feeling of reduced mental energy.

These symptoms can have many explanations, including stress, anemia, sleep disorders, medications, and other illnesses, so testing is important when symptoms persist.

9. Shortness of Breath

Shortness of breath can occur in advanced kidney disease.

One possible reason is fluid buildup, which can contribute to breathing difficulties. Anemia associated with kidney disease can also contribute to fatigue and breathlessness.

Because shortness of breath can also indicate heart or lung problems, sudden or severe breathing difficulty requires prompt medical evaluation.

10. Blood in the Urine

Blood in the urine, known as hematuria, can sometimes be associated with kidney disease.

Urine may appear pink, red, or cola-colored, although blood may also be detectable only through laboratory testing.

Blood in urine can have many causes—including urinary infections, kidney stones, and other urinary-tract conditions—so it should be medically evaluated rather than automatically attributed to kidney disease.

The Most Important Point: Kidney Disease Can Be Silent

Having none of these symptoms does not necessarily mean your kidneys are healthy.

Early chronic kidney disease often causes no noticeable symptoms. In fact, testing may be the only way to detect it at an early stage.

People with diabetes, high blood pressure, heart disease, or a family history of kidney failure have increased risk and should discuss appropriate kidney screening with a healthcare professional.

Which Tests Check Kidney Health?

Doctors commonly use blood and urine tests to evaluate kidney health.

A blood test can measure creatinine, which is used to calculate eGFR, an estimate of how well the kidneys are filtering blood.

A urine test can check for albumin or other proteins, which may indicate kidney damage.

The National Kidney Foundation specifically identifies eGFR and urine albumin-to-creatinine ratio (uACR) as important tests for assessing kidney health in people at risk.

When Should You Seek Medical Attention?

Contact a healthcare professional if you have persistent swelling, repeated foamy urine, blood in your urine, significant changes in urination, unexplained fatigue, or other persistent symptoms.

Seek urgent medical care for severe shortness of breath, confusion, seizures, very little or no urine, or a sudden major deterioration in your condition. Acute kidney injury can develop rapidly and requires prompt treatment.

Final Thoughts

Your body can sometimes show clues when kidney function is deteriorating, but these symptoms are not a diagnosis. Many of them can occur with conditions unrelated to the kidneys.

The most important thing to remember is that kidney disease can remain silent for a long time. If you have risk factors or concerning symptoms, appropriate blood and urine testing can detect problems earlier and give you an opportunity to address the underlying cause.