What are tendonitis and tenosynovitis and what causes them?
Tendonitis and tenosynovitis are types of tendon injury. They can often occur together. Strictly speaking: • Tendonitis means inflammation of a tendon. (It is sometimes spelt tendinitis.) • Tenosynovitis means inflammation of the sheath that surrounds a tendon. (The sheath is called the synovium.) However, more recently, it is thought that inflammation of the tendon and the tendon sheath is not the whole picture in all cases. It is thought that most of the time there is an injury, or several repeated small injuries or tears, to the tendon. This may initially cause some inflammation of the tendon. But, in the longer term, if these injuries continue, it can lead to tendon damage (degeneration). These injuries typically occur when tendons are ‘overused’. For example, this may be after playing a lot of sport, or overuse in the course of your work. (Tenosynovitis commonly occurs around the wrist. Overuse by lots of writing, typing, assembly line work, etc, can trigger inflammation. This typ
