The three major types of arthritis that affects the shoulder are osteoarthritis, rheumatoid arthritis, and posttraumatic arthritis. The cause of shoulder arthritis depends on the type of arthritis you are affected by. Osteoarthritis of the shoulder is typically a result of old age. It most commonly affects the AC joint rather than the glenohumeral joint. Rheumatoid arthritis is caused by an inflammation in the joint lining. It can affect patients of any age and usually affects both shoulders. As its name suggests, posttraumatic arthritis is caused after an injury.
The most common symptom of shoulder arthritis is pain that worsens during activity. This pain may also increase with changes in the weather. The pain can be centered in the back of the shoulder (glenohumeral) or in the front of the shoulder (AC joint). Some patients may also experience limited mobility or have difficulty lifting their arms. Pain can also cause difficulty sleeping at night. Other symptoms include swelling, stiffness, and a feeling of grinding around the joints.