Biceps tendonitis is inflammation of the biceps tendon. It most often occurs from repetitive overuse of the same arm or shoulder. Overuse and repetitive motion can cause the tendon to swell, which causes pain. Options for treatment for biceps tendonitis include rest, activity modification, anti-inflammatory medications, and physical therapy. Arthritis of the shoulder is treated with medications, physical therapy, injections, cortisone shots, surgery, and joint replacement. Treatment depends on the severity and type of arthritis.