Everyday in my office I see a variety of patients who have made an appointment for their shoulder pain. They range in age from late teens to 90 years of age or even older. The vast majority of them are in the 40-60 year range.
The young patients that I see usually have a problem with shoulder instability. They may have fallen on their outstretched arm or shoulder and dislocated the joint. If this reoccurs again then there is almost a 100% chance that it will keep dislocating. This type of injury will require surgery to stabilize the joint and prevent arthritis.
More commonly is the 40-60 year old patient who complains of pain along the side or front of the shoulder. This usually occurs from a repetitive type of activity such as painting or working overhead. It also is quite common in people who have jobs that involve the same constant motion of the shoulder. Workers on an assembly line who use an impact gun or drill will often come in with shoulder pain. They describe the pain as sharp at times radiating down the side of the arm. It often prevents them from sleeping on that side at night. On exam there is tenderness, limited range of motion and sometimes weakness.
Xrays may show some findings of early arthritis, but many times it is normal. If I suspect a torn rotator cuff an MRI may be ordered. More often then not it is a bursitis. This is an inflammation of the sac between the roof of the shoulder and tendons. It responds well to a steroid injection with fairly quick relief. Physical therapy is also recommended to strengthen the shoulder and prevent reoccurrence.
If I determine that there is a torn rotator cuff then I discuss with the patient the options of surgery versus conservative treatment.
There are other causes of shoulder pain, but bursitis and rotator cuff injuries are the two main reasons: "why do I have shoulder pain?"