Trigger finger is locking of the finger in the bent or fist position.  It is usually worst in the mornings and after the finger unlocks it improves a bit through the day.  It is usually due to an inflammation of the tendon which is the pulley that connects muscles in the forearm to the bones of the fingers allowing for movement. Treatment can include topical anti-inflammatories, splints, cortisone injection and occasionally a minor surgical procedure to release the triggering finger.