Shoulder pain can be due to:
• Arthritis in the joints about the shoulder (gradual narrowing of the joints and loss of protective cartilage).
• Bursitis (inflammation of a fluid-filled sac, or bursa, that lies between tendon and skin or between tendon and bone). Normally a bursa protects the joint and helps make movement more fluid.
• Fractures of the shoulder bones.
• Frozen shoulder syndrome occurs when you don't move your shoulder because of pain or injury. The muscles or connective structures stiffen up inside the shoulder and make any motion painful and
difficult.
•Inflammation of nearby tendons, such as those connected to the bicep muscles of your arms, from overuse or injury.
• Dislocation of your shoulder, which is when the ball-shaped head of your arm comes out of the socket.