Skip to Content
Home > Wellness > Health Library > Baker's Cyst
A Baker's cyst is a pocket of fluid that forms a lump behind the knee.
It is also called a popliteal cyst. See a picture of a
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 causes no pain. When symptoms occur, they may include:
Sometimes the pocket of fluid behind the knee can tear open
and drain into the tissues of the lower leg. This can cause swelling and
redness in that part of the leg.
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
MRI, to see a picture of the inside of your knee.
A Baker's cyst may go away on its own.
If arthritis or another problem is causing the Baker's cyst, your doctor
may treat that problem. This usually makes the pain and swelling of a Baker's
cyst go away.
If a cyst does not go away, or if it is causing a
lot of pain, your doctor may drain the fluid with a needle. You also may be
given a shot of
steroid medicine to reduce swelling. You may need to
use a cane or crutch and wrap your knee in an elastic bandage. In rare cases, a
Baker's cyst is removed by surgery.
There are things you can do
at home to help you feel better.
Other Works Consulted
American Academy of Orthopaedic Surgeons and American Academy of Pediatrics (2010). Popliteal cyst. In JF Sarwark, ed., Essentials of Musculoskeletal Care, 4th ed., pp. 716–718. Rosemont, IL: American Academy of Orthopaedic Surgeons.
Rosenberg D, Amadera J (2015). Baker cyst. In WR Frontera et al., eds., Essentials of Physical Medicine and Rehabilitation, 3rd ed., pp. 331–334. Philadelphia: Saunders.
ByHealthwise StaffPrimary Medical ReviewerWilliam H. Blahd, Jr., MD, FACEP - Emergency MedicineE. Gregory Thompson, MD - Internal MedicineSpecialist Medical ReviewerKenneth J. Koval, MD - Orthopedic Surgery, Orthopedic Trauma
Current as ofMay 23, 2016
Current as of:
May 23, 2016
William H. Blahd, Jr., MD, FACEP - Emergency Medicine & E. Gregory Thompson, MD - Internal Medicine & Kenneth J. Koval, MD - Orthopedic Surgery, Orthopedic Trauma
To learn more about Healthwise, visit Healthwise.org.
© 1995-2016 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
I Want To...
Our interactive Decision Points guide you through making key health decisions by combining medical information with your personal information.
You'll find Decision Points to help you answer questions about:
Get started learning more about your health!
Our Interactive Tools can help you make smart decisions for a healthier life. You'll find personal calculators and tools for health and fitness, lifestyle checkups, and pregnancy.
Feeling under the weather?
Use our interactive symptom checker to evaluate your symptoms and determine appropriate action or treatment.