What is the definition of tendinitis?

The correct definition of tendinitis is inflammation of a tendon due to overuse or injury. Tendinitis typically occurs when a tendon, which connects muscle to bone, becomes irritated or inflamed due to repetitive movement or excessive strain. This inflammation can lead to pain, tenderness, and limited movement in the affected area. Common examples include tennis elbow and Achilles tendinitis, which are both related to the overuse of the respective tendons.

Understanding this definition helps clarify the nature of tendinitis as a condition primarily characterized by an inflammatory response, distinguishing it from other injuries such as fractures or ligament tears, which involve different structures (bones and ligaments, respectively) and different types of injuries.