What is chronic kidney disease?
Chronic kidney disease (CKD and chronic kidney disease) is when your kidneys are damaged and not working as well as they should. Your kidneys act like filters for your body, filtering waste, toxins and excess fluid from your blood. They also help with other functions like healthy bones and red blood cells. When your kidneys start to fail, they can no longer filter out waste products, which build up in your blood.
Kidney disease is called “chronic” because it causes a gradual decline in kidney function over time. CKD can lead to kidney failure, also known as end-stage renal disease. Not everyone with CKD will develop kidney failure, but the disease often worsens if left untreated. There is no cure for chronic kidney disease. However, there are steps you can take to slow kidney damage. Treatments such as dialysis and transplants are options for kidney failure (end-stage renal disease).
What do the kidneys do?
You have two kidneys. They are bean-shaped organs located in your back, on either side of your spine, just below your rib cage. Each kidney is about the size of your fist.
The kidneys have many jobs, but their main job is to purify the blood and eliminate toxins, waste products, and excess water in the urine. The kidneys also balance the levels of electrolytes (such as salt and potassium) and minerals in the body, make hormones that control blood pressure, make red blood cells, and keep bones strong. When the kidneys are damaged and no longer functioning properly, waste products can build up in the blood and make you sick.
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What are the 5 stages of chronic kidney disease?
There are five stages of chronic kidney disease. The stages are based on the ability of your kidneys to filter waste products from the blood. Blood and urine tests will determine what stage of CKD you are in.
Stages range from very mild (Stage 1) to kidney failure (Stage 5). Healthcare professionals determine the stage of kidney function based on your glomerular filtration rate (GFR), which is a number based on the amount of creatinine, a waste product, in your blood.
| Stage 1 | 90 and above | The kidneys are functioning normally, but there are signs of mild kidney damage. |
| Stage 2 | 60 to 89 | The kidneys are functioning normally, but there are signs of mild kidney damage. |
| Stage 3a | 45-59 years old | Your kidneys are not functioning properly and are mild to moderately damaged. This is the most common stage. You may notice symptoms at this stage. |
| Stage 3b | 30-44 years old | The kidneys show moderate damage and do not function properly. With proper treatment, most people remain at this stage and do not progress to stage 4. |
| Stage 4 | 15-29 years old | Your kidneys are severely damaged and no longer functioning properly. |
| Stage 5 | Under 15 | Your kidneys are approaching failure or have stopped functioning. At this stage, you may need kidney dialysis or a kidney transplant. |
| stage | ||
|---|---|---|
| Stage 1 | ||
| GFR (mL/min) | ||
| 90 and above | ||
| What it means | ||
| The kidneys are functioning normally, but there are signs of mild kidney damage. | ||
| Stage 2 | ||
| GFR (mL/min) | ||
| 60 to 89 | ||
| What it means | ||
| The kidneys are functioning normally, but there are signs of mild kidney damage. | ||
| Stage 3a | ||
| GFR (mL/min) | ||
| 45-59 years old | ||
| What it means | ||
| Your kidneys are not functioning properly and are mild to moderately damaged. This is the most common stage. You may notice symptoms at this stage. | ||
| Stage 3b | ||
| GFR (mL/min) | ||
| 30-44 years old | ||
| What it means | ||
| The kidneys show moderate damage and do not function properly. With proper treatment, most people remain at this stage and do not progress to stage 4. | ||
| Stage 4 | ||
| GFR (mL/min) | ||
| 15-29 years old | ||
| What it means | ||
| Your kidneys are severely damaged and no longer functioning properly. | ||
| Stage 5 | ||
| GFR (mL/min) | ||
| Under 15 | ||
| What it means | ||
| Your kidneys are approaching failure or have stopped functioning. At this stage, you may need kidney dialysis or a kidney transplant. |
How common is this condition?
Approximately 15% of adults in the U.S. have chronic kidney disease. Approximately 37 million people in the U.S. have chronic kidney disease.
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