The condition of “Trigger finger” (or Trigger Thumb) is when the tendons that control the small finger (or thumb) become inflamed or irritated, which leads to stiffness in the finger. This can happen when you repeatedly use your fingers to press down on something, like a trigger.

Trigger finger happens because tendons are rubbing together and irritating each other while they slide over one another. Over time, this rubbing can lead to inflammation and pain in the fingers.