Overview

What is kidney disease? An expert explains

Learn more from kidney doctor Andrew Bentall, M.D.

I'm Dr. Andrew Bentall, a kidney doctor at Mayo Clinic. I look after patients with kidney disease, either in the early stages, or with more advanced kidney disease considering dialysis and transplantation as treatment options. In this video, we'll cover the basics of chronic kidney disease. What is it? Who gets it? The symptoms, diagnosis and treatment. Whether you are looking for answers for yourself or for someone you love, we're here to give you the best information available.

Chronic kidney disease is a disease characterized by progressive damage and loss of function in the kidneys. It's estimated that chronic kidney disease affects about one in seven American adults. And most of those don't know they have it. Before we get into the disease itself, let's talk a little bit about the kidneys and what they do. Our kidneys play many important roles keeping our bodies in balance. They remove waste and toxins, excess water from the bloodstream, which is carried out of the body in urine. They helped to make hormones to produce red blood cells, and they turn vitamin D into its active form, so it's usable in the body.

There are quite a few things that can cause or put you at higher risk for chronic kidney disease. Some of them are not things that can be avoided. Your risk is simply higher if you have a family history of certain genetic conditions like polycystic kidney disease or some autoimmune diseases like lupus or IgA nephropathy. Defects in the kidney structure can also cause your kidneys to fail, and you have an increased risk as you get older. Sometimes, other common medical conditions can increase your risk. Diabetes is the most common cause of kidney disease. Both type 1 and type 2 diabetes. But also heart disease and obesity can contribute to the damage that causes kidneys to fail. Urinary tract issues and inflammation in different parts of the kidney can also lead to long-term functional decline. There are things that are more under our control: Heavy or long-term use of certain medications, even those that are common over-the-counter. Smoking can also be a contributing factor to chronic kidney disease.

Often there are no outward signs in the earlier stages of chronic kidney disease, which is grouped into stages 1 through 5. Generally, earlier stages are known as 1 to 3. And as kidney disease progresses, you may notice the following symptoms. Nausea and vomiting, muscle cramps, loss of appetite, swelling via feet and ankles, dry, itchy skin, shortness of breath, trouble sleeping, urinating either too much or too little. However, these are usually in the later stages, but they can also happen in other disorders. So don't automatically interpret this as having kidney disease. But if you're experiencing anything that concerns you, you should make an appointment with your doctor.

Even before any symptoms appear, routine blood work can indicate that you might be in the early stages of chronic kidney disease. And the earlier it's detected, the easier it is to treat. This is why regular checkups with your doctor are important. If your doctor suspects the onset of chronic kidney disease, they may schedule a variety of other tests. They may also refer you to a kidney specialist, a nephrologist like myself. Urine tests can reveal abnormalities and give clues to the underlying cause of the chronic kidney disease. And this can also help to determine the underlying issues. Various imaging tests like ultrasounds or CT scans can be done to help your doctor assess the size, the structure, as well as evaluate the visible damage, inflammation or stones of your kidneys. And in some cases, a kidney biopsy may be necessary. And a small amount of tissue is taken with a needle and sent to the pathologist for further analysis.

Treatment is determined by what is causing your kidneys to not function normally. Treating the cause is key, leading to reduced complications and slowing progression of kidney disease. For example, getting better blood pressure control, improved sugar control and diabetes, and reducing weight are often key interventions. However, existing damage is not usually reversible. In some conditions, treatment can reverse the cause of the disease. So seeking medical review is really important. Individual complications vary, but treatment might include high blood pressure medication, diuretics to reduce fluid and swelling, supplements to relieve anemia, statins to lower cholesterol, or medications to protect your bones and prevent blood vessel calcification. A lower-protein diet may also be recommended. It reduces the amount of waste your kidneys need to filter from your blood. These can not only slow the damage of kidney disease, but make you feel better as well. When the damage has progressed to the point that 85 to 90 percent of your kidney function is gone, and they no longer work well enough to keep you alive, it's called end-stage kidney failure. But there are still options. There's dialysis, which uses a machine to filter the toxins and remove water from your body as your kidneys are no longer able to do this. Where possible, the preferred therapy is a kidney transplant. While an organ transplant can sound daunting, it's actually often the better alternative, and the closest thing to a cure, if you qualify for a kidney transplant.

If you have kidney disease, there are lifestyle choices. Namely quit smoking. Consuming alcohol in moderation. If you're overweight or obese, then try to lose weight. Staying active and getting exercise can help not only with your weight, but fatigue and stress. If your condition allows, keep up with your routine, whether that's working, hobbies, social activities, or other things you enjoy. It can be helpful to talk to someone you trust, a friend or relative who's good at listening. Or your doctor could also refer you to a therapist or social worker. It can also be helpful to find a support group and connect with people going through the same thing. Learning you have chronic kidney disease and learning how to live with it can be a challenge. But there are lots of ways to help you to be more comfortable for longer before more drastic measures are needed. And even then, there is plenty of hope. If you'd like to learn even more about chronic kidney disease, watch our other related videos or visit mayoclinic.org. We wish you well.

Chronic kidney disease, also called chronic kidney failure, involves a gradual loss of kidney function. Your kidneys filter wastes and excess fluids from your blood, which are then removed in your urine. Advanced chronic kidney disease can cause dangerous levels of fluid, electrolytes and wastes to build up in your body.

In the early stages of chronic kidney disease, you might have few signs or symptoms. You might not realize that you have kidney disease until the condition is advanced.

Treatment for chronic kidney disease focuses on slowing the progression of kidney damage, usually by controlling the cause. But, even controlling the cause might not keep kidney damage from progressing. Chronic kidney disease can progress to end-stage kidney failure, which is fatal without artificial filtering (dialysis) or a kidney transplant.

How kidneys work

One of the important jobs of the kidneys is to clean the blood. As blood moves through the body, it picks up extra fluid, chemicals and waste. The kidneys separate this material from the blood. It's carried out of the body in urine. If the kidneys are unable to do this and the condition is untreated, serious health problems result, with eventual loss of life.

Symptoms

Signs and symptoms of chronic kidney disease develop over time if kidney damage progresses slowly. Loss of kidney function can cause a buildup of fluid or body waste or electrolyte problems. Depending on how severe it is, loss of kidney function can cause:

  • Nausea
  • Vomiting
  • Loss of appetite
  • Fatigue and weakness
  • Sleep problems
  • Urinating more or less
  • Decreased mental sharpness
  • Muscle cramps
  • Swelling of feet and ankles
  • Dry, itchy skin
  • High blood pressure (hypertension) that's difficult to control
  • Shortness of breath, if fluid builds up in the lungs
  • Chest pain, if fluid builds up around the lining of the heart

Signs and symptoms of kidney disease are often nonspecific. This means they can also be caused by other illnesses. Because your kidneys are able to make up for lost function, you might not develop signs and symptoms until irreversible damage has occurred.

When to see a doctor

Make an appointment with your doctor if you have signs or symptoms of kidney disease. Early detection might help prevent kidney disease from progressing to kidney failure.

If you have a medical condition that increases your risk of kidney disease, your doctor may monitor your blood pressure and kidney function with urine and blood tests during office visits. Ask your doctor whether these tests are necessary for you.

Causes

Chronic kidney disease occurs when a disease or condition impairs kidney function, causing kidney damage to worsen over several months or years.

Diseases and conditions that cause chronic kidney disease include:

  • Type 1 or type 2 diabetes
  • High blood pressure
  • Glomerulonephritis (gloe-mer-u-low-nuh-FRY-tis), an inflammation of the kidney's filtering units (glomeruli)
  • Interstitial nephritis (in-tur-STISH-ul nuh-FRY-tis), an inflammation of the kidney's tubules and surrounding structures
  • Polycystic kidney disease or other inherited kidney diseases
  • Prolonged obstruction of the urinary tract, from conditions such as enlarged prostate, kidney stones and some cancers
  • Vesicoureteral (ves-ih-koe-yoo-REE-tur-ul) reflux, a condition that causes urine to back up into your kidneys
  • Recurrent kidney infection, also called pyelonephritis (pie-uh-low-nuh-FRY-tis)

Risk factors

Factors that can increase your risk of chronic kidney disease include:

  • Diabetes
  • High blood pressure
  • Heart (cardiovascular) disease
  • Smoking
  • Obesity
  • Being Black, Native American or Asian American
  • Family history of kidney disease
  • Abnormal kidney structure
  • Older age
  • Frequent use of medications that can damage the kidneys

Complications

Chronic kidney disease can affect almost every part of your body. Potential complications include:

  • Fluid retention, which could lead to swelling in your arms and legs, high blood pressure, or fluid in your lungs (pulmonary edema)
  • A sudden rise in potassium levels in your blood (hyperkalemia), which could impair your heart's function and can be life-threatening
  • Anemia
  • Heart disease
  • Weak bones and an increased risk of bone fractures
  • Decreased sex drive, erectile dysfunction or reduced fertility
  • Damage to your central nervous system, which can cause difficulty concentrating, personality changes or seizures
  • Decreased immune response, which makes you more vulnerable to infection
  • Pericarditis, an inflammation of the saclike membrane that envelops your heart (pericardium)
  • Pregnancy complications that carry risks for the mother and the developing fetus
  • Irreversible damage to your kidneys (end-stage kidney disease), eventually requiring either dialysis or a kidney transplant for survival

Prevention

To reduce your risk of developing kidney disease:

  • Follow instructions on over-the-counter medications. When using nonprescription pain relievers, such as aspirin, ibuprofen (Advil, Motrin IB, others) and acetaminophen (Tylenol, others), follow the instructions on the package. Taking too many pain relievers for a long time could lead to kidney damage.
  • Maintain a healthy weight. If you're at a healthy weight, maintain it by being physically active most days of the week. If you need to lose weight, talk with your doctor about strategies for healthy weight loss.
  • Don't smoke. Cigarette smoking can damage your kidneys and make existing kidney damage worse. If you're a smoker, talk to your doctor about strategies for quitting. Support groups, counseling and medications can all help you to stop.
  • Manage your medical conditions with your doctor's help. If you have diseases or conditions that increase your risk of kidney disease, work with your doctor to control them. Ask your doctor about tests to look for signs of kidney damage.

Chronic kidney disease care at Mayo Clinic

Sept. 03, 2021
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