Table of Contents
What is chronic kidney disease?
Chronic kidney disease (CKD and chronic kidney disease) means there is damage to the kidneys and the kidneys are not functioning properly. The kidneys are like filters in the body, filtering waste, toxins, and excess water from the blood. It also helps with other functions, such as bone and red blood cell health. When the kidneys begin to function poorly, they are no longer able to filter waste products and they accumulate in the blood.
Kidney disease is called “chronic” because kidney function gradually declines over time. CKD can lead to kidney failure, also called end-stage kidney disease. Not all patients with CKD develop kidney failure, but the disease often worsens if untreated. There is no cure for chronic kidney disease. However, there are steps you can take to slow kidney damage. Options for kidney failure (end-stage kidney disease) include treatments such as dialysis and transplantation.
What do the kidneys do?
There are two kidneys. These are bean-shaped organs located toward your back, on either side of your spine, just below your rib cage. Each kidney is about the size of a fist.
The kidneys have many jobs, but their main job is to clean the blood and remove toxins, waste products, and excess water in the form of urine (pee). The kidneys also balance the amount of electrolytes (such as salt and potassium) and minerals in the body, produce hormones that control blood pressure, produce red blood cells, and keep bones strong. When the kidneys are damaged and do not function properly, waste products can build up in the blood and cause disease.
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What are the five stages of chronic kidney disease?
There are five stages of chronic kidney disease. The stages are based on how well the kidneys can filter waste products from the blood. Blood and urine tests can tell you what stage of CKD you are in.
The stages range from very mild (stage 1) to kidney failure (stage 5). Your healthcare provider determines your stage of kidney function based on your glomerular filtration rate (GFR). GFR is a number based on the amount of creatinine, a waste product, present in the blood.
| stage 1 | 90 or more | The kidneys are functioning normally, but there are signs of mild kidney damage. |
| stage 2 | 60～89 | Although your kidneys are functioning normally, there are increasing signs of mild kidney damage. |
| stage 3a | 45-59 | The kidneys are not functioning properly and show mild to moderate damage. This is the most common stage. You may notice symptoms at this stage. |
| stage 3b | 30～44 | The kidneys show moderate damage and are not functioning properly. With proper treatment, most people remain at this stage and never progress to stage 4. |
| stage 4 | 15-29 | You have very poor kidney function. Your kidneys are severely damaged and are barely functioning. |
| stage 5 | less than 15 | The kidneys are nearing failure or have stopped working. Kidney dialysis or a kidney transplant may be required at this stage. |
| stage | ||
|---|---|---|
| stage 1 | ||
| GFR (mL/min) | ||
| 90 or more | ||
| what it means | ||
| The kidneys are functioning normally, but there are signs of mild kidney damage. | ||
| stage 2 | ||
| GFR (mL/min) | ||
| 60～89 | ||
| what it means | ||
| Although your kidneys are functioning normally, there are increasing signs of mild kidney damage. | ||
| stage 3a | ||
| GFR (mL/min) | ||
| 45-59 | ||
| what it means | ||
| The kidneys are not functioning properly and show mild to moderate damage. This is the most common stage. You may notice symptoms at this stage. | ||
| stage 3b | ||
| GFR (mL/min) | ||
| 30～44 | ||
| what it means | ||
| The kidneys show moderate damage and are not functioning properly. With proper treatment, most people remain at this stage and never progress to stage 4. | ||
| stage 4 | ||
| GFR (mL/min) | ||
| 15-29 | ||
| what it means | ||
| You have very poor kidney function. The kidneys are severely damaged and are almost non-functional. | ||
| stage 5 | ||
| GFR (mL/min) | ||
| less than 15 | ||
| what it means | ||
| The kidneys are nearing failure or have stopped working. Kidney dialysis or a kidney transplant may be required at this stage. |
How common is this condition?
Approximately 15% of adults in the United States have chronic kidney disease. Approximately 37 million people in the United States live with chronic kidney disease.
