Tenosynovitis is a type of inflammation that affects the lining of the sheath surrounding tendons. It is a painful condition that can occur in any part of the body where tendons are present. Other words that are commonly used to refer to tenosynovitis include tendonitis, tendinitis, and peritendinitis. These terms essentially refer to the same condition and are often used interchangeably. Other medical terms that may be used to describe tenosynovitis include stenosing tenosynovitis, trigger finger, and De Quervain's tenosynovitis. Regardless of the term used, tenosynovitis can be difficult to manage, and treatment often involves a combination of rest, medication, and physical therapy.