What is trigger finger?

Explained by Dr. Badia

Trigger finger, also known as stenosing tenosynovitis or trigger digit, is a condition that affects the fingers, particularly the thumb and the fingers closest to the thumb (index, middle, and ring fingers). It’s characterized by the inability to smoothly and comfortably flex or extend the affected finger, as if pulling a trigger, hence the name “trigger finger.”

Here’s a detailed explanation of trigger finger:

Causes: Trigger finger occurs when the tendons that enable the fingers to flex and extend become irritated or inflamed. These tendons glide through a narrow tunnel or sheath, which allows for smooth movement. When the sheath becomes inflamed or thickened, it can constrict the tendon’s movement, resulting in a finger that catches or locks in a bent position before suddenly releasing, like pulling a trigger. The exact cause can be due to overuse, repetitive hand movements, inflammatory conditions, or sometimes it can occur without a specific cause.


Catching or Locking: The finger may catch or lock in a bent position and then suddenly pop straight, often accompanied by a snapping or clicking sensation.

Pain and Tenderness: There may be pain or tenderness at the base of the affected finger, especially when trying to move it.

Stiffness: The finger may feel stiff, making it difficult to flex or extend it fully.

Swelling: In some cases, there might be swelling or a bump at the base of the affected finger.

Limited Mobility: The condition can lead to reduced finger mobility, making it challenging to perform tasks that require finger movement.