Tendonitis (which is also sometimes spelled tendinitis) is a form of painful inflammation in the tendons, which are the chord-like parts of the body that connect muscles to bones. Usually caused by repetitive movements (like exercise or sitting in the same position for many hours), injuries or built-up inflammation over time, tendonitis can cause a lot of pain.
*Chronic tendonitis is a dull but constant soreness that feels worse when you first start to move. It then eases up as muscles get warmer.
*Acute tendonitis is a sharper pain that may keep you from moving the joint. The pain may eventually go away. But it's likely to return if the stressful motion is repeated.