Bursitis is the inflammation of the cushioning sacs between joints, called bursae. When the knee is affected, these sacs will begin to swell and place pressure on the adjacent parts of the knee.

5. Knee bursitis Where it hurts: It causes pain on the kneecap or just below the knee joint towards the inner side. What causes it: Knee bursitis occurs when one of the bursae in your knee becomes ...