Shoulder bursitis is an inflammation of the bursa in the shoulder, which causes pain and sometimes redness and swelling. Bursae are small, fluid-filled sacs found near joints that act as a cushion between moving parts in the joint to stop muscles, bones, and tendons from rubbing together. When a shoulder bursa gets irritated, it becomes inflamed and grows in size, which means there is less space in the shoulder for muscles and tendons to move around, causing pain and a loss of movement in the shoulder. Shoulder bursitis is most common in the subacromial bursa, which is a large bursa at the tip of the shoulder that helps with smooth movement when the arm is lifted above the head.

Symptoms of shoulder bursitis include a dull ache, sharp pain, or mild tenderness, shoulder stiffness or a feeling of swelling, painful range of motion, nighttime pain when lying on the affected side, and sharp or pinching pain with overhead shoulder motions. Most people who get shoulder bursitis also have shoulder tendinitis, which is damage to rotator cuff tendons. Other conditions that can cause shoulder pain include bone spurs or calcific tendinitis, dislocated shoulder, frozen shoulder, osteoarthritis, rotator cuff tears, and shoulder impingement syndrome.

Treatment for shoulder bursitis may include activity modification, immobilization with a splint, icing, injections, aspiration of the bursa (removing fluid with a syringe), antibiotics or anti-inflammatory pain medication. Surgery is rarely needed to treat bursitis. Rest and gentle exercises can also speed up recovery. To prevent bursitis of the shoulder, it is important to reduce strain on the shoulder joint.