A trigger finger results from a (sterile) inflammatory reaction of the flexor tendon or tendon sheath of a finger. The tendon sheath is the tube through which the tendon slides when the finger is bent. Inflammation causes a thickening in the tendon, preventing it from gliding smoothly through tendon sheath. The thickening usually occurs at the base of the finger in the palm of the hand. Sometimes, the finger eventually becomes completely stuck ('locked') and can no longer be stretched or bent. With help, the finger then shoots free again and this movement pattern is very similar to that of a finger pulling the trigger of a gun. Hence the name 'trigger finger'.

A trigger finger occurs mostly in women in the 45-65 age group. The most commonly affected fingers are the ring finger and thumb. A trigger finger often occurs in combination with carpal tunnel syndrome and Diabetes Mellitus (diabetes).

Complaints with a tripper finger

The classic symptoms of trigger finger begin with a mild pain or irritation when bending the finger or thumb. As symptoms increase, the palm of the hand may become painful when touched, where the entrance to the flexor tunnel is located. Sometimes a swelling can be felt that moves back and forth when bending or stretching the finger. As mentioned earlier, the finger sometimes remains in the bent position and one feels a click when it is released with assistance.