What is baker's cyst?

Baker's Cyst

Baker's cyst: Overview

A Baker's cyst is a swelling behind the knee. It may cause pain or stiffness when you bend your knee or straighten it all the way. Baker's cysts are also called popliteal cysts.

If you have arthritis or another condition that is the cause of the Baker's cyst, your doctor may treat that condition. This may relieve the pain and swelling.

A Baker's cyst may go away on its own. If not, or if it is causing a lot of discomfort, your doctor may give you a shot of steroid medicine to reduce swelling. In some cases, fluid is drained with a needle or the Baker's cyst is removed in surgery.

There are things you can do at home to reduce the swelling and pain, such as staying off your leg.

Baker's cyst

A Baker's cyst, also known as a popliteal cyst, is a pocket of joint fluid that forms a lump behind the knee. Often a Baker's cyst is painless, but occasionally this pocket of fluid can tear open and drain into the tissues of the lower leg, causing pain and swelling.

Symptoms include:

  • Swelling behind the knee that may increase when a person stands.
  • Discomfort behind the knee and into the upper calf, especially when the knee is completely bent or straight.

What are the symptoms of a Baker's cyst?

Often a Baker's cyst causes no pain. You may not notice symptoms unless the cyst becomes very large or it bursts. When symptoms occur, they may include tightness or stiffness behind the knee, swelling behind the knee that's worse when you stand, or pain behind the knee and into the upper calf.

How is a Baker's cyst treated?

A Baker's cyst may go away on its own. If it's caused by another problem, treating that problem may relieve pain and swelling. If a cyst doesn't go away or is painful, you may get a shot of steroid medicine to reduce swelling. In rare cases, fluid is drained or surgery is done.

How is a Baker's cyst diagnosed?

Your doctor will examine your knee and ask you questions about your past health and when the pain and swelling started. Your doctor may order tests, such as an ultrasound or an MRI, to see a picture of the inside of your knee.

How can you care for yourself when you have a Baker's cyst?

Home care can help you feel better. For example, rest your knee, and take an over-the-counter medicine, such as ibuprofen or naproxen, to reduce pain and swelling. Follow your doctor's instructions about how much weight you can put on your knee. Ask your doctor about using a cane, crutch, or elastic bandage.

Baker's Cyst

Baker's cyst

A Baker's cyst is a pocket of joint fluid that forms a lump behind the knee. It is also called a popliteal cyst.

What causes a Baker's cyst?

A Baker's cyst is caused when excess joint fluid is pushed into one of the small sacs of tissue behind the knee. When this sac fills with fluid and bulges out, it is called a cyst. The excess fluid is usually caused by conditions such as rheumatoid arthritis or osteoarthritis that irritate the knee. It may also be caused by an injury.

Baker's cyst: When to call

Call 911 anytime you think you may need emergency care. For example, call if:

  • You have chest pain, are short of breath, or you cough up blood.

Call your doctor now or seek immediate medical care if:

  • You have new or worse pain.
  • Your foot is cool or pale or changes color.
  • You have tingling, weakness, or numbness in your foot or toes.
  • You have signs of a blood clot in your leg (called a deep vein thrombosis), such as:
    • Pain in your calf, back of the knee, thigh, or groin.
    • New or worse redness or swelling in your leg.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • You do not get better as expected.

©2011-2024 Healthwise, Incorporated

The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.