8 Warning Signs of Kidney Failure That Should Never Be Ignored

Your kidneys work quietly around the clock, filtering waste and excess fluid from your blood, helping control blood pressure, balancing minerals, and supporting the production of red blood cells. Because kidney disease can develop gradually, however, many people may not realize that their kidney function is declining until the condition becomes more advanced.

Kidney failure does not usually appear suddenly without warning. In many cases, the body begins showing subtle changes as kidney function decreases. Some of these symptoms can also occur with many other conditions, so having one symptom does not automatically mean that your kidneys are failing.

Still, persistent or unexplained symptoms deserve medical attention.

Here are 8 potential warning signs that may occur with significant kidney problems.

1. Swelling in the Legs, Ankles, Feet, or Around the Eyes

Healthy kidneys remove excess sodium and fluid from the body.

When kidney function becomes impaired, the body may retain more fluid than it should. This can contribute to swelling, also called edema, particularly in the ankles, feet, lower legs, or sometimes around the eyes.

You may notice that shoes or socks suddenly feel tighter, or that pressing on swollen skin leaves a temporary indentation.

However, swelling can also be caused by heart disease, liver disease, certain medications, venous problems, and other conditions.

Persistent unexplained swelling should be evaluated by a healthcare professional.

2. Changes in Urination

Changes in urination can sometimes provide an important clue that something is affecting the urinary system or kidneys.

Depending on the underlying condition, a person may experience:

• Urinating more frequently, especially at night
• Producing much less urine than usual
• Foamy or unusually bubbly urine
• Blood in the urine
• Difficulty urinating
• Changes in the appearance of urine

Foamy urine can occur temporarily, but persistent or excessive foam may indicate protein in the urine, which can be associated with kidney damage.

Blood in the urine also has many possible causes and should not simply be assumed to be a kidney problem.

3. Unusual or Persistent Fatigue

Feeling tired after inadequate sleep or a stressful day is normal.

But persistent fatigue that doesn't improve with adequate rest can have many medical causes, including advanced kidney disease.

One reason is that healthy kidneys help produce erythropoietin, a hormone involved in red blood cell production. Chronic kidney disease can reduce erythropoietin production and contribute to anemia.

Anemia can cause symptoms such as:

Fatigue, weakness, reduced stamina, dizziness, headaches, and difficulty concentrating.

Because anemia has many possible causes, blood testing is necessary to determine what is actually happening.

4. Nausea, Loss of Appetite, or Unpleasant Taste

As kidney function becomes severely impaired, waste products can accumulate in the bloodstream.

This condition is sometimes called uremia.