Rheumatoid arthritis is a disease of the immune system. This is the system that protects you from infection. RA may cause pain and stiffness in your shoulder where the humerus (the bone of the upper arm) meets the shoulder socket. It can also affect the joint where your clavicle meets your scapula.
The cause of rheumatoid arthritis is not fully understood. Genetics and environmental factors may both play a role. When the disease is triggered, the body begins to attack its own healthy tissues. The body attacks the tissue that lines and protects your joints. Cartilage breaks down. This can allow bone to rub against bone. Bony spurs may form.
RA can cause pain, swelling and stiffness in your shoulder. It can limit your shoulder’s range of motion. You may feel grinding or popping sensations when you move your arm. RA often affects both sides of the body equally. If you have it in one shoulder, you are likely to have it in the other.
Treatment options may include rest and medications. You may need to modify your daily activities. You may benefit from physical therapy. You may also benefit from a surgical procedure.