Tendonitis is a common inflammatory condition that affects the tendons of the body and typically causes pain and discomfort. It can occur in various parts of the body, including the shoulders, elbows, wrists, knees, and ankles. Some synonyms for tendonitis include tendinitis, tenosynovitis, peritendinitis, and paratenonitis. Tendinitis and tendonitis are often used interchangeably, and both refer to the same inflammation of the tendon. Tenosynovitis is a specific type of tendonitis that affects the sheath that surrounds the tendon. Peritendinitis refers to inflammation of the tissue around the tendon, while paratenonitis is inflammation of the outer layer of tissue that surrounds the tendon.