Kidneys have many jobs vital to good health. They act as filters for your blood, removing waste, toxins, and surplus fluids.

They also help to:

  • regulate blood pressure and blood chemicals
  • keep bones healthy and stimulate red blood cell production

If you have chronic kidney disease (CKD), you’ve had damage to your kidneys for more than a few months. Damaged kidneys don’t filter blood as well as they should, which can lead to a variety of serious health concerns.

There are five stages of CKD and different symptoms and treatments associated with each stage.

The Centers for Disease Control and Prevention (CDC) estimates that 37 million U.S. adults have CKD, but most haven’t been diagnosed. It’s a progressive condition, but treatment can slow it down. Not everyone will advance to kidney failure.

To assign a CKD stage, your doctor must determine how well your kidneys are working.

One way to do this is with a urine test to assess your albumin-creatinine ratio (ACR). It shows if protein is leaking into the urine (proteinuria), which is a sign of kidney damage.

ACR levels are staged as follows:

A1lower than 3mg/mmol, a normal to mild increase
A23–30mg/mmol, a moderate increase
A3higher than 30mg/mmol, a severe increase

Your doctor may also order imaging tests, such as an ultrasound, to assess the structure of your kidneys.

A blood test measures creatinine, urea, and other waste products in the blood to see how well the kidneys work. This is called the estimated glomerular filtration rate (eGFR). A GFR of 100 mL/min is normal.

This table highlights the five stages of CKD. More information about each stage follows the table.

StageDescriptionGFRPercent of kidney function
1normal to highly functioning kidney>90 mL/min>90%
2mild decrease in kidney function60–89 mL/min60–89%
3Amild-to-moderate decrease in kidney function45–59 mL/min45–59%
3Bmild-to-moderate decrease in kidney function30–44 mL/min30–44%
4severe decrease in kidney function15–29 mL/min15–29%
5 kidney failure<15 mL/min<15%

Glomerular filtration rate (GFR)

GFR, or glomerular filtration rate, shows how much blood your kidneys filter in 1 minute.

The formula to calculate GFR includes body size, age, sex, and ethnicity. With no other evidence of kidney problems, a GFR as low as 60 could be considered normal.

GFR measurements can be misleading if, for example, you’re a body builder or have an eating disorder.

Healthline

In stage 1, there’s very mild damage to the kidneys. They’re quite adaptable and can adjust for this, allowing them to keep performing at 90 percent or better.

At this stage, CKD is likely to be discovered by chance during routine blood and urine tests. You may also have these tests if you have diabetes or high blood pressure, the top causes of CKD in the United States.

Symptoms

Typically, there are no symptoms when kidneys function at 90 percent or better.

Treatment

You can slow disease progression by taking these steps:

If you don’t already see a kidney specialist (nephrologist), ask your general physician to refer you to one.

In stage 2, kidneys are functioning between 60 and 89 percent.

Symptoms

At this stage, you might still be symptom free. Or symptoms are nonspecific, such as:

  • fatigue
  • itching
  • loss of appetite
  • sleep problems
  • weakness

Treatment

It’s time to develop a relationship with a kidney specialist. There’s no cure for CKD, but early treatment can slow or stop progression.

It’s important to address the underlying cause. If you have diabetes, high blood pressure, or heart disease, follow your doctor’s instructions for managing these conditions.

It’s also important to maintain a good diet, get regular exercise, and manage your weight. If you smoke, ask your doctor about smoking cessation programs.

Stage 3A means your kidney is functioning between 45 and 59 percent. Stage 3B means kidney function is between 30 and 44 percent.

The kidneys aren’t filtering waste, toxins, and fluids well and these are starting to build up.

Symptoms

Not everyone has symptoms at stage 3. But you may have:

  • back pain
  • fatigue
  • loss of appetite
  • persistent itching
  • sleep problems
  • swelling of the hands and feet
  • urinating more or less than usual
  • weakness

Complications may include:

  • anemia
  • bone disease
  • high blood pressure

Treatment

It’s important to manage underlying conditions to help preserve kidney function. This may include:

  • high blood pressure medications such as angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers
  • diuretics and a low salt diet to relieve fluid retention
  • cholesterol-lowering medications
  • erythropoietin supplements for anemia
  • vitamin D supplements to address weakening bones
  • phosphate binders to prevent calcification in the blood vessels
  • following a lower protein diet so your kidneys don’t have to work as hard

You’ll probably need frequent follow-up visits and tests so adjustments can be made if necessary.

Your doctor can refer you to a dietitian to make sure you’re getting all the nutrients you need.

Stage 4 means you have moderate-to-severe kidney damage. They’re functioning between 15 and 29 percent, so you may be building up more waste, toxins, and fluids in your body.

It’s vital that you do all you can to prevent progression to kidney failure.

According to the CDC, 48 percent of people with severely reduced kidney function aren’t even aware they have it.

Symptoms

Symptoms can include:

  • back pain
  • chest pain
  • decreased mental sharpness
  • fatigue
  • loss of appetite
  • muscle twitches or cramps
  • nausea and vomiting
  • persistent itching
  • shortness of breath
  • sleep problems
  • swelling of the hands and feet
  • urinating more or less than usual
  • weakness

Complications can include:

  • anemia
  • bone disease
  • high blood pressure

You’re also at increased risk of heart disease and stroke.

Treatment

In stage 4, you’ll need to work very closely with your doctors. In addition to the same treatment as earlier stages, you should start discussions about dialysis and kidney transplant should your kidneys fail.

These procedures take careful organization and a lot of time, so it’s wise to have a plan in place now.

Stage 5 means your kidneys are working at less than 15 percent capacity or you have kidney failure.

When that happens, the buildup of waste and toxins becomes life-threatening. This is end-stage renal disease.

Symptoms

Symptoms of kidney failure can include:

  • back and chest pain
  • breathing problems
  • decreased mental sharpness
  • fatigue
  • little to no appetite
  • muscle twitches or cramps
  • nausea or vomiting
  • persistent itching
  • trouble sleeping
  • severe weakness
  • swelling of the hands and feet
  • urinating more or less than usual

The risk of heart disease and stroke is growing.

Treatment

Once you have complete kidney failure, life expectancy is only a few months without dialysis or a kidney transplant.

Dialysis isn’t a cure for kidney disease, but a process to remove waste and fluid from your blood. There are two types of dialysis, hemodialysis and peritoneal dialysis.

Hemodialysis

Hemodialysis is done at a dialysis center on a set schedule, usually 3 times a week.

Before each treatment, two needles are placed in your arm. They’re attached to a dialyzer, which is sometimes referred to as an artificial kidney. Your blood is pumped through the filter and returned to your body.

You can be trained to do this at home, but it requires a surgical procedure to create vein access. Home dialysis is done more frequently than dialysis in a treatment center.

Peritoneal dialysis

For peritoneal dialysis, you’ll have a catheter surgically placed into your abdomen.

During treatment, dialysis solution flows through the catheter into the abdomen, after which you can go about your normal day. A few hours later, you can drain the catheter into a bag and discard it. This must be repeated 4 to 6 times a day.

A kidney transplant involves replacing your kidney with a healthy one. Kidneys can come from living or deceased donors. You won’t need dialysis, but you’ll have to take anti-rejection drugs for the rest of your life.

There are 5 stages of chronic kidney disease. Stages are determined with blood and urine tests and the degree of kidney damage.

While it’s a progressive disease, not everyone will go on to develop kidney failure.

Symptoms of early stage kidney disease are mild and can be easily overlooked. That’s why it’s important to have regular checkups if you have diabetes or high blood pressure, the leading causes of kidney disease.

Early diagnosis and management of coexisting conditions can help slow or prevent progression.