Shoulder pain can stem from one or more of the following causes: 1  Strains from overexertion. 2  Tendonitis from overuse. 3  Shoulder joint instability. 4  Dislocation. Collar or upper arm bone fractures.  Frozen 1  shoulder. Pinched nerves (also called radiculopathy)
Joint pain can affect one or more joints. Joint pain can be caused by many types of injuries or conditions. It may be linked to arthritis, bursitis, and muscle pain. No matter what causes it, joint pain can be very bothersome. Some things that can cause joint pain are: Autoimmune diseases such as rheumatoid arthritis and lupus.
The most common cause of pain in a single joint is an injury, such as a sprain. Additional causes for pain in one joint include bursitis, tendinitis, and septic arthritis. Common causes of pain in multiple joints include osteoarthritis, rheumatoid arthritis, gout, or pseudogout.