Description
The flexor tendon can become irritated as it slides through the tendon sheath tunnel. As it becomes more and more irritated, the tendon may thicken and nodules may form, making its passage through the tunnel more difficult.
The tendon sheath may also thicken, causing the opening of the tunnel to become smaller.
If you have trigger finger, the tendon becomes momentarily stuck at the mouth of the tendon sheath tunnel when you try to straighten your finger. You might feel a pop as the tendon slips through the tight area and your finger will suddenly shoot straight out.