Your Kidneys and You

Kidneys play a vital role in maintaining your health. Learn more about where your kidneys are, what your kidneys do, and why they are important.

Where Are My Kidneys?

The kidneys are located below the rib cage, one on each side of the spine, toward the back of the body. They are protected by the lower part of your rib cage.

Each bean-shaped organ is about 4 to 5 inches long, about the size of an adult fist. Although they are small, your kidneys work hard to keep the rest of your body in balance.

Black background with a translucent body. Kidneys and bladder are in orange with the kidneys on either side of the spine and the bladder in the pelvis.

What Do My Kidneys Do?

Your kidneys work to keep you healthy. The main job of your kidneys is to filter your blood. All of the blood in your body goes through the kidneys several times a day. The kidneys remove waste from the blood and adjust salts, fluid, and minerals. This waste is turned into urine, which then travels to the bladder and is eliminated.

Most people have two kidneys. But, your body can function well with only one kidney.

Why Are My Kidneys Important?

Normal healthy kidneys...

Remove excess fluid and waste

Your kidneys filter blood and make urine. Urine contains excess fluid and waste. Filtering your blood helps keep excess fluid and waste from building up in your body.

Control blood pressure

Kidneys need a certain level of pressure to work properly. They use hormones and fluid levels to control this pressure. For example, if the pressure inside the kidneys is too low, the kidneys make a hormone that causes blood vessels to constrict. This has the effect of increasing blood pressure.

The kidneys work to maintain normal blood pressure. This keeps your heart, brain, and other organs healthy.

Help make red blood cells

Your kidneys make a hormone called erythropoietin. Erythropoietin tells bone marrow to make red blood cells. Red blood cells carry oxygen from your lungs to your brain and vital organs. Red blood cells provide the energy you need for daily activities. If you don’t have enough red blood cells, you develop anemia. Anemia can make you feel weak and tired.

Help keep bones healthy

The kidneys make an active form of vitamin D. You need vitamin D to absorb calcium and phosphorus. Calcium and phosphorus are important minerals for bone health. The kidneys also balance calcium and phosphorus so your body has the right amount.

Control pH levels

Your body functions best with a healthy balance of acids and bases in your blood. As cells break down, they make acids. The foods you eat can either increase or lower the amount of acid in your body.

pH level is a measure of acids and bases. Your kidneys balance your pH level by either removing or adjusting the amount of acid and buffering agents.

What Happens When My Kidneys Slow Down or Stop Working?

When your kidneys slow down or stop working, your body can’t remove excess fluids and waste. Over time, toxins build up and make you feel sick. Damaged kidneys affect every part of your body. This condition is called Chronic Kidney Disease (CKD).

A man in pain, holding his stomach and head.