Most shoulder problems only affect a small area and should last a relatively short time.
But sometimes the problem in your shoulder could be part of a wider, long-term condition such as, osteoarthritis or polymyalgia rheumatica.
It’s fairly common for people with rheumatoid arthritis to have pain and swelling in their shoulders.
Osteoarthritis is less likely to affect your shoulders than other joints, unless you’ve injured them in the past.
There are several other possible causes of shoulder pain, such as:
inflammation, where your shoulder becomes hot, red, swollen and painful as a natural reaction to an infection or injury
damage to the muscles and tendons around the shoulder
tension in the muscles between the neck and shoulder – this is usually down to your posture in your upper back or neck, and is often linked the way you stand or sit when you’re using a computer or at work
inflammation in the bursa – a fluid-filled cushion which normally helps the muscles and tendons slide smoothly over the shoulder bones
damage to the bones and cartilage, which can be caused by arthritis.
It’s also possible the pain you’re feeling in your shoulder is coming from a problem in another part of your body, such as your neck.
Problems in your neck can make your shoulder blade or upper outer arm painful. When this happens it’s known as referred pain or radiated pain. If you’re feeling a tingling sensation in your hand or arm, as well as pain in your shoulder, it’s likely to be from a problem in your neck.