What Are the Stages of Chronic Kidney Disease?

Chronic kidney disease (CKD) is a chronic condition in which the kidneys are not working as well as they should. There are 5 stages of chronic kidney disease. Each stage is measured by the amount of normal kidney function you have.¹

How are the stages determined?

Kidney function is measured using a blood test called the GFR and also a urine test. GFR stands for glomerular filtration rate.¹

The heart pumps blood into millions of tiny filters in the kidney called nephrons. Each nephron is made of a glomerulus and a tubule. The glomerulus filters your blood, and the tubule returns nutrition to your blood and removes waste. The GFR test measures how well your kidneys are doing these jobs.²

The GFR score mirrors the percent of normal kidney function you have. People whose kidneys still work well have a GFR score of 60 or higher. This means their kidneys are working at about 60 percent or higher of normal function. As CKD gets worse, the GFR number gets lower.³

What are the 5 stages of CKD?

The 5 stages of CKD are:¹

• Stage 1 – GFR of 90 or higher
• Stage 2 – GFR of 60 to 89
• Stage 3 – GFR of 30 to 59
• Stage 4 – GFR of 15 to 29
• Stage 5 – GFR lower than 15

Stage 3 is sometimes broken into 2 substages:¹

• 3a – GFR of 45 to 59
• 3b – GFR of 30 to 44

As you move from early stages to later stages, your risk of kidney disease getting worse gradually becomes more likely. For example, at stage 1 you have a low risk of progression. By stage 3b, you have a high risk of developing end-stage kidney disease, also called kidney failure.¹

The goal at each stage of kidney disease is to take steps to slow down the damage to your kidneys.¹

What happens at each stage of kidney disease

Stage 1

In stage 1, there is mild damage but the kidneys are still working about as well as normal. Your GFR score will be 90 or higher. There are often no symptoms, but you may start to have signs of kidney damage such as protein in your urine.¹

Stage 2

Stage 2 is still considered mild kidney damage. Your GFR score will range from 60 to 89. The kidneys still work well enough that you may not have any symptoms.¹

Stage 3

Stage 3 may indicate mild to severe kidney damage. A GFR score of 45 to 59 is considered stage 3a and means you have mild to moderate kidney damage. A GFR of 30 to 44 means you have moderate to severe kidney damage.¹

At stage 3, waste and fluid may begin to build up in your body and cause other health problems. Most people begin to notice symptoms such as feeling weak or tired, or swelling in the hands or feet. Your blood pressure may creep higher, and bone disease may occur.¹

The good news is that with treatment and lifestyle changes, many people can stop kidney damage from becoming worse and moving to stage 4 or 5.¹

Stage 4

GFR ranges from 15 to 29 in stage 4. At this point, the kidneys are severely damaged and close to not working at all. Symptoms that may have begun in stage 3 are more noticeable and troublesome.^1,2

Stage 4 symptoms include:⁴

• High blood pressure
• Anemia (not enough red blood cells in your body)
• Kidney-related bone disease
• Protein in your urine
• High potassium and phosphorus levels in the blood
• Buildup of acid in the body (metabolic acidosis)
• Weakness and tiredness
• Swelling in the arms and legs
• Peeing more or less than normal
• Lower back pain
• Muscle cramps
• Feeling nauseous or vomiting
• Loss of appetite

At stage 4, you need to begin seeing a nephrologist if you are not already. These are doctors who specialize in the kidneys. Your nephrologist will work with you to slow down the damage to your kidneys.⁴

There are many medicines and lifestyle changes that can preserve what kidney function you have left. The medicines you take will depend on what caused your kidney disease. For example, you may need blood pressure drugs to control your blood pressure. You also may need to avoid pain medicines that harm the kidneys. A dietitian can help you follow a kidney-friendly eating plan.⁴

If your kidneys are close to failure, your doctor will talk to you about your options. These options include:^4,5

• Dialysis
• Kidney transplant (not an option for everyone)
• Conservative management, which is refusing dialysis or transplant but continuing medical care

Stage 5

Stage 5 means your kidneys are barely working or have stopped working completely. Your GFR will be lower than 15. Your kidneys are no longer filtering waste out of your blood. As those products build up in your body, you begin to feel very sick.¹

As your kidneys begin to fail, the symptoms that began in stage 4 get worse and more symptoms begin.⁶

Stage 5 symptoms include:⁶

• High blood pressure
• Anemia
• Kidney-related bone disease
• Protein in your urine
• High potassium and phosphorus levels in the blood
• Buildup of acid in the body (metabolic acidosis)
• Weakness and tiredness
• Swelling in the arms, hands, legs and feet
• Heachaches
• Lower back pain
• Muscle cramps
• Feeling nauseous or vomiting
• Loss of appetite
• Trouble breathing
• Changes in skin color

When your kidneys stop working, you enter what is called end-stage kidney disease or end-stage renal disease. You will need to see your doctor more often and probably take more medicines. If your kidneys fail and you do not start dialysis or get a kidney transplant, you will die.⁶

You may be able to slow or stop the damage to your kidneys in the first 3 stages with medicine and lifestyle changes. Once you reach stage 4, it is harder to slow the damage. If you have kidney disease, make sure your doctor monitors your GFR regularly. Also ask them about how you can slow the progression.¹

Learn more about each stage of chronic kidney disease:

• Stage 1, 2, and 3a
• Stage 3b and 4
• Stage 5