Chronic kidney disease (CKD) occurs when a person experiences a gradual, usually permanent, loss of kidney function over a period of months to years. CKD is divided into five stages* of increasing severity, based on the kidneys’ ability to cleanse the blood of toxic waste and excess fluid.

As explained by the American Kidney Fund, doctors measure how well the kidneys filter waste with an estimated glomerular filtration rate (eGFR). eGFR is the number given when testing the blood for creatinine, a muscle waste product. eGFR helps gauge how much blood is being filtered through the kidneys and what the most appropriate course of treatment may be. 

The five stages based on eGFR

Stage 1

An eGFR equal to or over 90 signifies healthy kidneys that are working well, but with some signs of damage, such as protein in the urine or physical organ damage.

Stage 2

An eGFR of 60-89 means mild kidney damage. The kidneys are mostly healthy and working well, but other signs of kidney damage exist, such as protein in the urine or physical organ damage. To slow disease progression, your doctor may recommend limiting dietary protein, measuring blood sugar, quitting smoking, and doing regular exercise.

Stage 3

An eGFR of 30-59 indicates some kidney damage. Divided into two sub-stages (3A for an eGFR of 45-59 and 3B for 30-44), many people with Stage 3 do not have any symptoms, while others may have swelling in the hands and feet, back pain, and more or less urination than normal. A patient in Stage 3 may have high blood pressure, anemia (lack of oxygenated blood, due to low red blood cells or low hemoglobin), bone disease, and/or other complications.

Stage 4

An eGFR of 15-29 means the kidneys are moderate to severely damaged. You should pay close attention if you or someone you know is within this eGFR range because it is the final stage before kidney failure.

Patients with Stage 4 kidney disease may have the following symptoms:

• urinating more or less than normal;
• swelling in hands and feet; and
• back pain.

To prevent a worsening of kidney function in Stage 4 patients:

• Meet with a nephrologist (kidney doctor) who will determine the best treatment plan for you, including how frequently you should check your kidneys.
• Your doctor will suggest visiting a dietitian, who will assist you in eating healthy and making sure you’re getting the nutrients you need.
• Discuss preparations for kidney failure with your nephrologist. Dialysis to help cleanse the blood (hemodialysis or peritoneal) or a kidney transplant will be necessary to sustain life.

Stage 5

An eGFR under 15 means the kidneys are “very close to failure or have completely failed,” reports the American Kidney Fund. Upon failure, a person can become very ill from toxic waste accumulation in the blood. A patient with kidney failure may experience swelling in the hands and feet, itching, muscle cramps, nausea, vomiting, loss of appetite, back pain, urinating more or less than normal, and trouble breathing and sleeping. Dialysis or kidney transplantation must be done to continue life.

*American Kidney Fund. Stages of Chronic Kidney Disease (CKD).