First things first: if your thumb joint is swollen, hot, and inflamed you should seek medical care immediatelyas this could be a sign of a severe infection. In a normally functioning hand, tendons run through sheaths or pulleys to the fingers to make them bend. With trigger thumb, medically known as stenosing tenosynovitisthe tendon sheaths a tunnel-like structure that holds the tendon to the bone become inflamed and thickened, making it difficult for the tendon to smoothly glide through the sheath to bend the affected finger.
The tendons act as cords that pull your fingers down into a fist and then relax as you straighten the fingers. Think of the tendon as a line on a fishing rod and the pulleys as the eyelets that keep the line in contact with the rod as it bends and straightens. A knot in the line may make the line catch as it is pulled through the eyelet.
Trigger finger is a condition in which one of your fingers gets stuck in a bent position. Your finger may bend or straighten with a snap — like a trigger being pulled and released. It occurs when inflammation narrows the space within the sheath that surrounds the tendon in the affected finger. If trigger finger is severe, your finger may become locked in a bent position.
Rest assured that the most common causes of finger-popping are not a problem at all. Many people can make their fingers pop, often called cracking their knuckles. The sound you hear is thought to be caused by air bubbles moving in the fluid that surrounds your joints.
These pulleys hold the tendons close to the bone. This is similar to how a line is held on a fishing rod Figure 1. Trigger finger occurs when the pulley becomes too thick, so the tendon cannot glide easily through it Figure 2.
Trigger finger and trigger thumb are two conditions that go hand-in-hand literally. This condition, at best, is mildly irritating and, at worst, is extremely painful and debilitating. This results in many common symptoms including finger stiffness, a popping or clicking sensation, tenderness or even a visible bump at the base of your finger, and finger locking in a bent position. In most cases, many different at home treatments can remedy the catching of the digit in a bent position and the pain upon release.
Back to Health A to Z. This can make it difficult to move the affected finger or thumb and can result in a clicking sensation. It usually affects the thumb, ring finger or little finger.
Trigger finger is a condition that causes pain, stiffness, and a sensation of locking or catching when you bend and straighten your finger. The flexor tendons are long cord-like structures that attach the muscles of the forearm to the bones of the fingers. When the muscles contract, the flexor tendons allow the fingers to bend.