Kidney disease is often called a “silent” condition for a reason: many people don’t realize anything is wrong until significant damage has already occurred. Your kidneys work around the clock to filter waste, balance fluids, regulate blood pressure, and keep your body’s chemistry stable. When they start to struggle, the early signals can be subtle—easy to blame on stress, aging, or a busy lifestyle. But learning to recognize these warning signs may help you seek medical attention sooner and protect your long-term health.

Here are 10 kidney warning signs that many people overlook.

1. Persistent fatigue or weakness

If your kidneys can’t filter waste properly, toxins build up in the blood. This can make you feel unusually tired, weak, or mentally “foggy,” even after a full night’s sleep.

2. Swelling in the feet, ankles, or around the eyes

One of the most common signs of kidney trouble is fluid retention. When kidneys can’t remove extra water and salt, swelling may appear in the lower legs, ankles, or even the face.

3. Changes in urination

Watch for urinating more often (especially at night), producing less urine than usual, or noticing urine that is foamy, dark, or contains blood. These changes may signal kidney stress or damage.

4. Foamy urine

Foamy or bubbly urine could be a sign of protein leaking into the urine, a condition called proteinuria. It can be one of the earliest detectable signs of kidney problems.

5. Back or flank pain

Pain in the lower back or side area—especially on one side—may be linked to kidney stones, infection, or inflammation. While not all kidney problems cause pain, persistent discomfort should be checked.

6. Dry, itchy skin

Healthy kidneys help maintain the right balance of minerals and nutrients in your blood. When they fail, skin may become extremely dry or itchy due to waste buildup or mineral imbalances.

7. Muscle cramps

Electrolyte imbalances, especially low calcium or changes in potassium levels, can lead to frequent cramps—often in the legs and feet.

8. Loss of appetite or nausea

A buildup of toxins can affect digestion and appetite. People may feel nauseous, lose interest in food, or experience unexplained weight loss.

9. Trouble sleeping

When waste products build up, the body becomes more uncomfortable, leading to poor sleep. Some individuals also develop restless legs or nighttime cramps.

10. Unusual skin changes or rashes

In some cases, kidney disease may lead to visible skin changes—rashes, irritation, or unusual discoloration—because waste is not being filtered effectively. Persistent unexplained skin issues can be a warning sign.