Causes of tendonitis
NHS Choices Medical Reference
Tendonitis is caused by overuse of a tendon or injury. It may be the result of:
- a sports-related injury, or
- a repetitive strain injury (repeated overuse of muscles), which can occur in the workplace.
A tear in the tendon because of injury may cause inflammation (swelling).
For reasons that are not known, tendonitis tends to occur more commonly in people with diabetes than in the general population.
Also, tenosynovitis (inflammation of the sheath surrounding the tendon) is sometimes associated with rheumatoid arthritis.
For more information on these conditions, see Useful links.