Bursitis is the inflammation of one or more bursae (small sacs) of synovial fluid in the body. The bursae rest at the points where internal functionaries, such as muscles and tendons, slide across bone. Healthy bursae create a smooth, almost frictionless functional gliding surface making normal movement painless. When bursitis occurs, however, movement relying upon the inflamed bursa becomes difficult and painful. Moreover, movement of tendons and muscles over the inflamed bursa aggravates its inflammation, perpetuating the problem.

Causes

Bursitis is commonly caused by repetitive movement and excessive pressure. Elbows and knees are the most commonly affected. Inflammation of the bursae might also be caused by other inflammatory conditions such as rheumatoid arthritis. Although infrequent, scoliosis might cause bursitis of the shoulders; however, shoulder bursitis is more commonly caused by overuse of the shoulder joint and related muscles.

Traumatic injury is another cause of bursitis. The inflammation irritates because the bursa no longer fits in the original small area between the bone and the functionary muscle or tendon. When the bone increases pressure upon the bursa, bursitis results.

Symptoms

Bursitis symptoms vary from local joint pain and stiffness, to burning pain that surrounds the joint around the inflamed bursa. In this condition, the pain usually is worse during and after activity, and then the bursa and the surrounding joint become stiff the next day in the morning.