The following are the common causes of shoulder pain:
Rotator cuff injury
Repetitive overhead arm movements, heavy lifting or other forms of trauma can strain the rotator cuff tendons and lead to tendinitis. Tendinitis can also develop due to chronic degeneration. The pain is felt mainly when raising the arm outwards and upwards from the body. When tendinitis is present, there is an increased risk of a rotator cuff tear occurring. The tear can be partial or complete and results in weakness when trying to raise the arm.
Impingement syndrome
Also known as painful arc, this condition is directly caused by rotator cuff tendinitis. The affected tendons are thickened and inflamed and get squeezed or impinged by the edge of the shoulder blade when moving or raising the arm.
Frozen shoulder
Also known as adhesive capsulitis, this is a condition in which the movement of the shoulder becomes severely restricted due to the growth of abnormal bands of tissue (called adhesions) between joint surfaces and a lack of synovial fluid to lubricate the joint. Frozen shoulder commonly occurs between the ages of 40 to 60 and can occur after a rotator cuff impingement, a tendon tear, or even minor injury. The problem usually resolves on its own, but this can take up to three years.
Shoulder dislocation
A shoulder dislocation occurs when the head of the humerus is forced out of the shoulder socket, usually as a result of a sudden injury or from overuse. When the ball of the humerus comes just partially out of the socket, this is called a partial dislocation or subluxation. Once the ligaments, tendons, and muscles around the shoulder become loose or torn, dislocations can occur repeatedly. Recurring dislocations cause pain and unsteadiness when raising the arm or moving it away from the body. Repeated episodes of subluxations or dislocations lead to an increased risk of developing arthritis.
Bursitis
Bursae are small fluid-filled sacs that aid in cushioning pressure points and reducing friction between the bones and ligaments or tendons. Bursitis can cause pain and swell in the affected area, particularly with motion.
Osteoarthritis (OA)
OA is the most common form of arthritis and is a chronic condition characterized by the breakdown of the cartilage that cushions the ends of the bones. This causes the bones to rub against each other, causing pain, stiffness and loss of movement in the joint. In the shoulder, OA often occurs after an injury.
A shoulder fracture usually occurs from trauma or a fall. The most commonly fractured areas in the shoulder are the clavicle and the head of the humerus. A shoulder fracture usually causes severe pain and bruising.
Referred pain from the neck
Sometimes, shoulder pain actually originates from the neck. A prolapsed intervertebral disc in the neck, for example, can cause impingement on nerves that travel through the shoulder all the way to the arm and hand.
