Bursitis is inflammation of the fluid filled sac which when working properly, cushions and reduces friction in joints such as the shoulder. Bursitis is often caused by repetitive motions. Some common locations for bursitis is knee, hip, elbow, but the most common being shoulder from excessive overhead movement.
Treatment is primarily by temporary rest of that limb, stopping the activity which aggravated the bursa and constant icing and or heating the region. Including anti-inflammatory pain medicine in the treatment will further reduce joint swelling. Pendulum exercises of letting gravity move the limb in a slow rhythmic movement will lubricate the joint, helping healing.