A Baker cyst is a fluid-filled sac behind your knee.
Baker cysts can happen when too much fluid builds up in your knee joint. The fluid bulges out at the back of your knee.
Baker cysts are more likely if you have:
Your doctor sometimes diagnoses a Baker cyst by examining your knee. Sometimes, doctors do imaging tests, such as:
If the Baker cyst has burst and caused calf swelling, doctors do ultrasound and other tests to check to see if you have a blood clot Deep Vein Thrombosis (DVT) Thrombosis is when a blood clot (called a thrombus) blocks a blood vessel. Deep vein thrombosis (DVT) is when a blood clot forms inside a large vein. Usually the vein is deep in your leg, but... read more in the veins in your leg.
Small Baker cysts don't need treatment and sometimes go away on their own. Doctors will treat any knee problem that is causing the Baker cyst. If the cyst is bigger and bothers you, doctors may:
Rarely, doctors do surgery to remove the cyst.