OK the below I got from a medical site. It shows bursitis and arthritis are differen, though symptoms and treatment can often be the same. I have arthritis, and when it plays up it is horrendously painful. Usual treatment, keep training and the pain goes away, or is replaced by something else, not medical guidance, in fact downright stupid, but still what I do.
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Arthritis and bursitis can be difficult to differentiate. Arthritis is joint inflammation with associated degeneration of connective tissue and bone. Bursitis is inflammation of the bursa, a sac-like cavity surrounding joints that is filled with fluid that reduces friction caused by movement. There are more than 150 bursa in the body. Most people have heard the term "water on the knee." This is often caused by bursitis.
Arthritis is common in weight-bearing joints such as the hips and knees. Bursitis is common in the shoulders, elbows, big toe and hips.
Direct trauma, joint infection or muscle stress and arthritis are common causes of bursitis. Arthritis is generally caused by age- related wearing of cartilage and connective tissues, leading to bone degeneration. It can also be caused by autoimmune disorders such as rheumatoid arthritis. Gout is a common cause of arthritis.
Treatment is similar for both arthritis and bursitis. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen sodium, ice, rest and steroid injections make up the primary course of therapy. If infection is the cause, treatment with antibiotics is necessary. For severe cases that last longer than a few weeks or if you have major swelling, the bursa may need to be drained. In rare cases, removal may be necessary.