Trigger finger is characterized by the agonizing pain that makes the fingers or the thumb to fasten or hold the fingers in a flexed condition. This is usually caused by inflammatory tendons found inside a restrictive containment known as a tendon sheath. The usual infected area is the hard, tissue connector of the muscles of the arm to the finger and the bones of the thumb. This works together allowing one to flex and move the fingers and the thumb. An inflammatory tendon may cause the fingers to fall apart or disengaged when it is flexed.