Stage 3 chronic kidney disease is one of the five stages of chronic kidney disease. This stage is divided into two subgroups, stage 3a (mild to moderate kidney damage) and stage 3b (moderate to severe kidney damage). This means that your kidneys don't work as well as they should.

Kidneys remove waste products and extra fluids from the blood and flush them from your body as urine. When your kidneys don't work right, wastes build up in your blood and make you sick. This can cause problems such as high blood pressure, anemia, and problems with your bones.

The stages of chronic kidney disease are determined mostly by the estimated glomerular filtration rate (eGFR). Glomerular filtration is the process that the kidneys use to filter the blood, removing excess wastes and fluids. The eGFR is a number that shows how well the kidneys filter the blood.

The two subgroups for stage 3 chronic kidney disease are based on their eGFR.

• Stage 3a has an eGFR from 45 to 59.
• Stage 3b has an eGFR from 30 to 44.

You may not have symptoms yet. But this stage is when they usually start to appear. Symptoms of stage 3 chronic kidney disease may include:

• Swelling in your hands or feet.
• Pain in your lower back.
• Urinating more or less often than usual.
• Urine that is foamy or darker in color than usual.
• Feeling weak and tired.
• Muscle cramps.
• Trouble sleeping.

Your doctor will ask you about past kidney problems. You will be asked if you have a family history of kidney disease. Your doctor will also want to know what medicines you take. This includes prescription and over-the-counter medicines.

Your doctor will do blood and urine tests to check how well your kidneys are working. This will help your doctor see how well your kidneys filter your blood. You may have other tests to help rule out other problems that could be causing your symptoms.

You also may have a test such as an ultrasound or CT scan. These tests let your doctor look at a picture of your kidneys. This can help your doctor measure the size of your kidneys and see if anything is blocking your urine flow.

In some cases, your doctor may take a tiny sample of kidney tissue (biopsy) to help find out what caused the kidney disease.

Chronic kidney disease is usually caused by another condition. So the first step is to treat the disease that is causing kidney damage.

Diabetes and high blood pressure cause most cases of chronic kidney disease. If you keep your blood pressure and blood sugar in a target range, you may be able to slow or stop the damage to your kidneys. Losing weight and getting more exercise can help. You may also need to take medicines.

Chronic kidney disease is a complex problem. You will probably need to take a number of medicines and have many tests when you have kidney disease. To stay as healthy as possible, work closely with your doctor. And take your medicines exactly the way your doctor says to.

Lifestyle changes are an important part of your treatment. Taking these steps can help slow down kidney disease and reduce your symptoms. These steps may also help with high blood pressure, diabetes, and other problems that make kidney disease worse.

• Be active. For many people, walking is a good choice. Try for at least 30 minutes on most days of the week.
• Follow a diet that is healthy for your kidneys. A dietitian can help make an eating plan with the right amount of salt (sodium), protein, and fluids.
• If you smoke, try to quit. If you can't quit, cut back as much as you can. Smoking can make chronic kidney disease worse. If you need help quitting, talk to your doctor about stop-smoking programs and medicines. These can increase your chances of quitting for good.
• Avoid medicines that can harm your kidneys. These include nonsteroidal anti-inflammatory drugs (NSAIDs). Examples of these are ibuprofen and celecoxib. Let your doctor know all of the prescription and over-the-counter medicines, vitamins, and herbs you take. And talk to your doctor before you take anything new.
• Avoid or limit alcohol, marijuana, or other drugs. If you need help decreasing your use, talk to your doctor.

Go to all your appointments and follow-up visits. Your doctor will use blood and urine tests to regularly check how well your kidneys are working and decide if you need changes in your treatment plan.