Diseases and Conditions
Baker's cyst
Overview
Symptoms
Causes
Complications
Diagnosis
Treatment
Lifestyle and home remedies
Preparing for an appointment
Causes
A lubricating fluid called synovial (sih-NO-vee-ul) fluid helps your leg swing smoothly and reduces friction between the moving parts of your knee.
But sometimes the knee produces too much synovial fluid, resulting in buildup of fluid in an area on the back of your knee (popliteal bursa), causing a Baker's cyst. This can happen because of:
- Inflammation of the knee joint, such as occurs with various types of arthritis
- A knee injury, such as a cartilage tear