What is the primary characteristic of tenosynovitis?

The primary characteristic of tenosynovitis is the inflammation of a tendon and its synovial sheath. This condition occurs when the sheath, which encases the tendon and allows for smooth movement, becomes irritated or inflamed. The inflammation can lead to pain, swelling, and difficulty moving the affected joint. This is particularly common in repetitive use injuries or conditions like rheumatoid arthritis, where the protective and lubricating function of the synovial fluid is compromised.

Other aspects associated with tenosynovitis may include the presence of pain during movement and signs of swelling around the joint. However, the defining feature remains the inflammation specifically of both the tendon and its sheath. Recognizing this helps in diagnosing and treating the condition effectively, addressing both the tendon and the surrounding structures.