Tendonitis is a condition in which the tendon, a fibrous chord that attaches muscle to bone or muscle to muscle, develops inflammation. Inflammation can occur to the tendon itself or to the lining of the tendon called the tendonous sheath, although usually the inflammation occurs in both areas simultaneously.
Tendons are usually very painful and tender to the touch, and pain results from movement of the involved joint. Often, the joint motion becomes restricted. Pain can become very severe depending on the degree of inflammation, and can radiate to the joints above and below the affected joint. In addition, the inflamed tendons can have a "creaking" quality due to "friction rubs" from the inflammation itself, and may become swollen. Bone enlargement around the affected tendon can also occur.
Types: There are two types of tendonitis: inflammation of the tendons themselves, and inflammation of the tendonous sheath that lines the tendons.
Tendonitis can be caused by decreased circulation to the tendons from repeated or chronic trauma. The most common repeated or extreme trauma is excessive exercise and/or strain. Certain diseases can also cause tendonitis, such as rheumatoid arthritis, autoimmune disorders, gout, Reiter's syndrome (an inflammatory syndrome), excessively high blood cholesterol levels, and sexually transmitted diseases.