Shoulder pain can be a result of injury or disease of the shoulder joint. Injury can affect any of the ligaments, bursae, or tendons surrounding the shoulder joint. Injury can also affect the ligaments, cartilage, menisci (plural for meniscus), and bones of the joint. The design of the shoulder joint is such that it sacrifices stability for mobility. As an extremely mobile joint that plays a central role in the action of a major extremity, the shoulder is at risk for injury. Common injuries of the shoulder can lead to inflammation of the bursae (bursitis) or tendons (tendonitis) and result in rotator cuff dysfunction as well as instability and frozen shoulder. Fracture of the bones of the shoulder (such as from biking falls) can cause intense shoulder pain.
Pain can also occur in the shoulder from diseases or conditions that involve the shoulder joint (including arthritis), the soft tissues and bones surrounding the shoulder, or the nerves that supply sensation to the shoulder area. Occasionally, shoulder pain can be a result of a heart attack. It is unusual for cancer to cause shoulder pain.