trigger-finger ~ What Causes Trigger Finger? Trigger finger can be caused by a repeated movement or forceful use of the finger or thumb. Rheumatoid arthritis, gout, and diabetes also can cause trigger finger. So can grasping something, such as a power tool, with a firm grip for a long time. Trigger finger is more common in women than men and tends to happen most often in people who are 40 to 60 years old.