Many people consider the shoulder to be a single joint; however, it actually is a combination of several different joints, tendons, and muscles. These structures combine to allow great mobility and range of motion. However, that mobility often leads to problems with instability or impingement of the bony structures or soft tissues located in the shoulder region. Such problems can cause pain, either with or without movement. Most shoulder issues fall into one of four main categories: tendon inflammation (either bursitis or tendonitis), instability, arthritis, or fracture. Less common shoulder pain causes include tumors, infection, or nerve problems. Injuries that lead to shoulder pain may be acute or chronic in nature. Those who suffer acute injuries that cause immediate pain in the shoulder should seek medical attention as soon as possible. To diagnose the specific cause of the pain, tests such as X-rays, MRIs, ultrasounds, CT scans, or other diagnostic imaging tools may be used. Treatment of shoulder pain varies widely depending on the type and severity of the issue and may include lifestyle and activity changes, physical therapy to improve shoulder strength and flexibility, administration of anti-pain and anti-inflammatory medications, and in severe cases, surgery. However, the vast majority of people who experience shoulder pain respond to non-surgical treatment.