Tenosynovitis is the inflammation of the fluid-filled sheath (called the synovium) that surrounds a tendon. Symptoms of tenosynovitis include pain, swelling and difficulty moving the particular joint where the inflammation occurs. When the condition causes the finger to "stick" in a flexed position, this is called "stenosing" tenosynovitis, commonly known as "trigger finger". This condition often presents with comorbid tendinitis.