About the Kidneys

The kidneys are a pair of organs located on either side of the spine, below the rib cage. They function like the body's maintenance crew, cleaning the blood and removing waste and extra fluid that becomes urine.

The kidneys’ jobs include:

• Managing the concentration of electrolytes (such as sodium, potassium, calcium, and phosphorus) in the body
• Controlling the balance of fluid and electrolytes in and outside every cell
• Balancing the water in the body
• Acting as filters that selectively conserve vital molecules and remove toxins through urine
• Regulating the body's pH

The kidneys also produce various hormones and vitamins that control blood pressure, red blood cell production, and bone health.

What happens if the kidneys are not working?

The kidneys may not work normally for many reasons, including diabetes, high blood pressure, genetic disease, autoimmune conditions, developmental abnormalities, infections, or exposure to certain medications or toxins. 

There are five stages of chronic kidney disease, ranging from one (mild) to five (severe).

If the kidneys have severe dysfunction, the body is unable to discard unnecessary electrolytes, fluids, and toxins. When toxins build up in the body, they create symptoms like fatigue, breath that smells of ammonia, loss of appetite, nausea, vomiting, swelling, and decreased urine production.

Electrolyte imbalances, especially in potassium, can have significant negative effects on the heart. In severe cases, kidney failure can be life-threatening and may require dialysis or kidney transplantation for treatment.

Symptoms of kidney disease

For the vast majority of patients, kidney disease may be asymptomatic. This is why it is so important to monitor blood and urine tests. Interventions early in the disease course (rather than waiting until symptoms develop) lead to better outcomes.

At the more severe stages of kidney disease, there are several signs and symptoms, which may include:

• Fatigue or generalized weakness
• Difficulty sleeping
• Nausea, vomiting, loss of appetite
• Itchy, dry skin
• Changes in urination, such as foamy urine and/or decreased overall daily urine production
• Swelling throughout the body and/or shortness of breath (due to retention of fluid)

Diagnosing kidney disease

The mild to moderate stages of kidney disease usually do not involve symptoms. Testing—such as blood and urine tests—is the only way to know how your kidneys are working.

Consider getting checked for kidney disease if you have:

• Diabetes
• High blood pressure
• Heart disease
• Family history of kidney failure

Catching kidney disease early gives you more options to protect your health and stop symptoms from getting worse.

Kidney Conditions

Many conditions can affect the kidneys and lead to chronic kidney disease, including:

• Diabetic nephropathy
• Hypertensive kidney disease
• Cystic kidney disease
• Kidney cancer
• Kidney stones
• Glomerulonephritis (like lupus nephritis), acute kidney injury (AKI) from sepsis, or exposure to medications or toxins

Treatments for kidney disease

A nephrologist is a doctor who specializes in the kidneys. They know how the kidneys affect the entire body and diagnose and treat kidney problems, disease, and failure. 

Depending on the type and severity of kidney disease, your doctor may consider treatment options such as:

• Lifestyle and/or dietary changes
• Medications to manage symptoms and/or underlying conditions and slow the progression of chronic kidney disease
• Monitoring and regular checkups
• Dialysis and/or kidney transplantation (in severe cases)

This page was reviewed by Vladimir Mushailov, MD, Assistant Professor of Medicine at the Vagelos College of Physicians and Surgeons.