Baker’s Cyst

Medically Reviewed by Tyler Wheeler, MD on September 23, 2022

What Is a Baker’s Cyst?

A Baker’s cyst is a fluid-filled sac behind your knee. It often causes a bulge and a feeling of tightness. You might hear your doctor call it a popliteal cyst.

Symptoms of a Baker’s Cyst

It might not cause any symptoms, but they may include:

  • Swelling behind your knee
  • Swelling in your leg
  • Knee pain
  • Stiffness -- you won’t be able to bend your knee

Causes of Baker’s Cysts

Causes of a Baker's cyst may include:

  • Swelling in the knee. This happens when the fluid that lubricates your knee joint increases. When pressure builds up, fluid squeezes into the back of the knee and creates the cyst.
  • Arthritis. People with all forms of arthritis often have Baker’s cysts.
  • Injury. A sports-related injury or other blow to the knee can cause A Baker's cyst.
  • Gout. This type of arthritis, which results from the buildup of uric acid in the blood, can lead to a Baker’s cyst.

Baker’s Cyst Diagnosis

See your doctor if you have any of the symptoms listed above and they’re causing problems.

They’ll examine you to rule out conditions that are more serious, like a blood clot (deep vein thrombosis).

They may also order an imaging test to get a better look, such as:

Baker’s Cyst Treatment and Home Treatment

You may not need any treatment for a Baker's cyst. They aren’t dangerous and tend to go away on their own. But there are things you can do at home to ease your pain and make yourself more comfortable:

  • Keep it cold. Apply a cold pack to the affected area. It’ll help keep the swelling down. A compression wrap might also help.
  • Take medication. For pain (and to ease inflammation), take an over-the-counter medication like ibuprofen.
  • Rest your leg. Keep it raised above your heart level when possible. This will keep down swelling. You may want to use a compression bandage, and a cane or crutch when you walk, to keep pressure off your leg.

If these at-home treatments don’t work, see your doctor. They may suggest:

  • Steroids. These can help lessen inflammation.
  • Exercise. A physical therapist can teach you gentle exercises, to help improve your range of motion, and strengthening moves, to build up the muscles around your knee. This could ease your symptoms.
  • Aspiration. Your doctor can drain the cyst. They’ll likely do it with the aid of an ultrasound. This treatment may not work if your case is severe.
  • Surgery. If you’re in serious pain or if the cyst makes it hard for you to move your knee, this might be an option. But it’ll work only if your doctor also treats the issue that caused the Baker’s cyst to begin with, such as arthritis.

If your leg turns red or darker and starts to swell, see your doctor right away. This could mean your Baker’s cyst has burst. You may notice fluid leak out. Your body will eventually absorb the extra fluid in your leg after a few weeks. Keep your leg propped up to help with swelling, and talk to your doctor about a prescription for medication to help with pain.

Can I Prevent a Baker’s Cyst?

Possibly -- by preventing knee injuries in the first place. Wear the right shoes when you work out. Be sure to warm up before you exercise. And if you do get a knee injury, take care of it right away. See your doctor if it doesn’t get better.

Baker’s Cyst Complications

Sometimes, the cysts break open. This can cause pain, swelling, and bruising on the back of your knee and calf. The pain might get worse when you fully extend your knee or when you’re active.

These symptoms can feel like the same ones you’d get if you had a blood clot in your leg, which can be serious. See your doctor to be sure it’s not.

Show Sources


Mayo Clinic: “Diseases and Conditions: Baker’s Cyst,” “Baker’s cyst.”

John Hopkins Arthritis Center: “Baker’s Cysts and Fullness in the Back of the Knee.”

Gov.UK: “Baker’s Cyst.”

Harvard Medical School: “Ask the Doctor: How Do You Treat a Baker’s Cyst?”

Orthopedics: “Popliteal Cysts: A Current Review.”

Saint Luke’s Health System: “Baker’s Cyst.”

National Health Service (U.K.): “Baker’s cyst.”

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