Bursae are fluid-filled sacks of tissue that lubricate areas of motion within the body and are essential for proper function. The subacromial bursa lies beneath the acromion process of the scapula (shoulder blade) and the rotator cuff. Bursitis is inflammation of the bursa that causes the tissue to swell. Pain increases as the tissue gets compressed.
Recurrent episodes of bursitis may indicate a more serious condition and should be evaluated by your doctor. X-rays will not show bursitis but may help diagnose an underlying condition; sometimes an MRI or ultrasound is necessary to further define the problem.
Pain with active motion, especially raising the arm above the head, is the primary symptom. Bursitis is common with overuse injuries and with instability of the shoulder, but can represent a more serious tear within the rotator cuff.
Bursitis cannot be prevented in all cases, but in some instances there are actions that can reduce the risk and severity. Avoid repetitive motions and placing significant pressure on the joint for an extended period of time.