Learning About the Stages of Chronic Kidney Disease

Having chronic kidney disease means that for some time your kidneys have not been working the way they should. Your kidneys have the important job of filtering your blood. They remove waste products and extra fluid and flush them from your body as...

What is chronic kidney disease?

Having chronic kidney disease means that for some time your kidneys have not been working the way they should. Your kidneys have the important job of filtering your blood. They remove waste products and extra fluid and flush them from your body as urine.

When your kidneys don't work right, wastes build up in your blood and make you sick. Chronic kidney disease is also called chronic renal failure or chronic renal insufficiency.

There are five stages of chronic kidney disease:

  • Stage 1
  • Stage 2
  • Stage 3
  • Stage 4
  • Stage 5

How are the stages of kidney disease determined?

The stages of chronic kidney disease are determined mostly by the estimated glomerular filtration rate (eGFR). Glomerular filtration is the process that the kidneys use to filter the blood, removing excess wastes and fluids. The eGFR is a number that shows how well the kidneys filter the blood. It's one way to measure kidney function. Your doctor will also use a test that measures the amount of protein in your urine.

The eGFR is often calculated using a formula that includes a person's age, sex, and serum creatinine (say "kree-AT-uh-neen") levels. The lower the eGFR number, the worse the kidney function. This number is an estimate. It may not be a good measure of kidney health in some people, such as the very young or very old, amputees, or people who have obesity.

What does each stage mean?

Stage 1 (eGFR 90 or above)

There is kidney damage without symptoms.

  • Your doctor will try to find the cause of your kidney disease and may begin treatment.
  • You'll work with your doctor to manage other health problems, such as diabetes and high blood pressure.
  • You'll see your doctor regularly to check how well your kidneys are working.

Stage 2 (eGFR 60–89)

There is a mild decline in kidney function.

  • Your doctor will estimate how quickly kidney disease is progressing.
  • You'll work with your doctor to manage other health problems, such as diabetes and high blood pressure.
  • You'll see your doctor regularly to check how well your kidneys are working.

Stages 3a (eGFR 45–59) and 3b (eGFR 30–44)

In stage 3a, there is a mild to moderate decline in kidney function. In stage 3b, there is a moderate to severe decline in kidney function.

  • Your doctor may check for problems caused by kidney disease. These include anemia and bone disease. You'll begin treatment if needed.
  • You'll see your doctor regularly to check how well your kidneys are working.

Stage 4 (eGFR 15–29)

There is a severe decline in kidney function.

  • You'll work with your doctor to decide what type of treatment you want if kidney failure develops.
  • You'll continue treatment and get tested to see how well your kidneys are working.

Stage 5 (eGFR below 15)

There is kidney failure.

  • You'll start dialysis, have a kidney transplant, or choose palliative care.
  • You'll continue to see your doctor for treatment and testing.

What are the symptoms?

Most people don't have symptoms early on. This is called the "silent" phase of the disease. But symptoms can start to appear a few months after your kidneys have stopped working as well as they should. Symptoms vary depending on the stage of kidney disease.

Stages 1 and 2

Most people don’t have symptoms at these stages. But your doctor may notice signs when testing for kidney damage or other health conditions. These signs could include:

  • Swelling of your hands or feet, high blood pressure, a urinary tract infection, and protein in your urine.
  • Kidney damage that shows up in an ultrasound, CT scan, MRI, or kidney biopsy.

Stage 3

You may not have symptoms yet. But this stage is when they usually start to appear. Symptoms may include:

  • Swelling in your hands or feet.
  • Pain in your lower back.
  • Urinating more or less often than usual.
  • Urine that is foamy or darker in color than usual.
  • Feeling weak and tired.
  • Muscle cramps.
  • Trouble sleeping.

Stage 4

Symptoms at this stage may include:

  • High blood pressure.
  • Anemia.
  • Bone disease.
  • Feeling weak and tired.
  • Swelling in your arms or legs.
  • Pain in your lower back.
  • Muscle cramps.
  • Feeling sick to your stomach or vomiting.
  • Loss of appetite.

Stage 5

Symptoms at this stage may include:

  • Feeling weak and tired.
  • Feeling sick to your stomach or vomiting.
  • Loss of appetite.
  • Trouble breathing.
  • Changes in skin color.
  • Producing little or no urine.
  • Swelling in your arms, hands, legs, or feet.
  • Headaches.
  • Pain in your lower back.
  • Muscle cramps.

How is it treated?

Chronic kidney disease is usually caused by another condition. So the first step is to treat the disease that is causing kidney damage.

Diabetes and high blood pressure cause most cases of chronic kidney disease. If you keep your blood pressure and blood sugar in a target range, you may be able to slow or stop the damage to your kidneys. Losing weight and getting more exercise can help. You may also need to take medicines.

Chronic kidney disease is a complex problem. You will probably need to take a number of medicines and have many tests when you have kidney disease. To stay as healthy as possible, work closely with your doctor. And take your medicines exactly as your doctor says to.

Lifestyle changes are an important part of your treatment. Taking these steps can help slow down kidney disease and reduce your symptoms. These steps may also help with high blood pressure, diabetes, and other problems that make kidney disease worse.

  • Be active. For many people, walking is a good choice. Try for at least 30 minutes on most days of the week.
  • Follow a diet that is healthy for your kidneys. A dietitian can help make an eating plan with the right amount of salt (sodium), protein, and fluids.
  • If you smoke, try to quit. If you can't quit, cut back as much as you can. Smoking can make chronic kidney disease worse. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.
  • Avoid medicines that can harm your kidneys. These include nonsteroidal anti-inflammatory drugs (NSAIDs). Examples of these are ibuprofen and celecoxib. Let your doctor know all of the prescription and over-the-counter medicines, vitamins, and herbs you take. And talk to your doctor before you take anything new.
  • Avoid or limit alcohol, marijuana, or other drugs. If you need help decreasing your use, talk to your doctor.

Go to all your appointments and follow-up visits. Your doctor will use blood and urine tests to regularly check how well your kidneys are working and decide if you need changes in your treatment plan.

What happens if kidney disease gets worse?

When kidney function falls below a certain point, it's called kidney failure. Kidney failure affects your whole body. It can cause serious heart, bone, and brain problems and make you feel very ill. Untreated kidney failure can be life-threatening.

When you have kidney failure, you will probably have two choices: Start dialysis to filter wastes and extra fluid from your blood, or get a new kidney (transplant). Both of these treatments have risks and benefits. Talk with your doctor to decide which would be best for you.

Glossary

Dialysis is a treatment for kidney failure that helps filter waste products from the blood when the kidneys are not working properly. The two main types of dialysis are hemodialysis and peritoneal dialysis.

  • Hemodialysis uses a man-made membrane (dialyzer) to filter wastes and remove extra fluid from the blood. It is usually done in a hospital or outpatient dialysis center 3 times a week. Some types of hemodialysis are done at home.
  • Peritoneal dialysis uses the lining of the abdomen (peritoneal membrane) and a solution (dialysate) to remove wastes and extra fluid from the body. Treatment can be done at home over several sessions each day or for several hours at night.

Kidney failure caused by chronic kidney disease occurs when kidney damage is so severe that a person needs dialysis or a kidney transplant to maintain life. Kidney failure often occurs after kidney damage has been present for 10 years or more.

Diabetes and high blood pressure are the most common causes of kidney failure in the United States.

Kidney failure can be measured by how well the kidneys are able to filter wastes from the blood. This is called the estimated glomerular filtration rate, or eGFR. Kidney failure usually occurs when the eGFR falls to below 15% of what is expected in a person with normal kidney function.

Kidney failure is treated with dialysis, which helps filter waste products from the blood when the kidneys are not working properly, or with kidney transplant.

Kidneys and their location in the body

The kidneys are two bean-shaped organs located on either side of the spine, at the small of the back. The kidneys filter wastes from the blood and help balance water, salt, and mineral levels in the blood.

Wastes filtered out of the blood are carried out of the body as urine. Urine flows through tubes (ureters) to the bladder, where it is stored until a person is ready to urinate. The waste and urine then leave the bladder and exit the body through a tube called the urethra.