Baker's cyst
Overview
A Baker's cyst (popliteal cyst) is a fluid-filled lump at the back of the knee. It may get better on its own or by treating the condition causing it, but you should get any lumps checked by a GP.
Symptoms
The main symptom of a Baker's cyst is a soft lump at the back of the knee. The lump may be your only symptom, but you may also have: knee or leg paintightness, stiffness or aching in your kneedifficulty bending your kneeclicking in your knee Your symptoms may be worse after walking.
Causes
Sometimes there is no particular cause of a Baker's cyst, especially in children. In adults they usually happen when another health condition causes damage to the knee joint, like: a knee injuryosteoarthritisorrheumatoid arthritisgout Anyone can get a Baker's cyst, but they are more common in people aged 35 to 70.
Treatment
A Baker's cyst does not always need treatment. Sometimes, particularly in children, it will get better on its own. If the Baker's cyst is caused by an underlying condition, your symptoms will usually get better when that condition is treated. But other treatments for a Baker's cyst can include: painkillersa painkilling injection (hydrocortisone injection) in your kneephysiotherapydraining fluid out of the cystsurgery to repair damage to your knee joint – it's rare to have surgery to remove a Baker's cyst A Baker's cyst can take a few months to a few years to get better.