According to the National Institutes of Health, up to 38% of MRIs on knees discover popliteal cysts, otherwise known as Baker’s cysts. These cysts form when joint-lubricating fluid fills a pouch near the back of the knee. This event can cause an unsightly bulge that can be extremely painful. 

What Causes Baker’s Cysts?

Our knees naturally produce joint-lubricating fluid called synovial fluid. When the knee produces too much fluid, the excess can fill the back and of the knee and create a cyst. A variety of causes exist for Baker’s cysts, which also means there are a variety of ways a flare-up can occur, such as the following…