Trigger finger occurs when tendons in the finger or thumb are inflamed, preventing free movement and causing a finger to catch or lock in position.
Tendons are the bands of tissue that connect to the fingers and thumbs, helping to bend and straighten them.
Tendons usually glide smoothly through tendon sheaths. But sometimes tendons become inflamed and swollen, impeding free movement. Also, prolonged irritation of a tendon sheath can scar and thicken the sheath so it hinders the smooth movement of the tendon. With this condition, when you bend your finger it pulls the inflamed tendon through the narrowed tendon sheath, making it click or pop.
A simple operation can be performed to open the tendon sheath and release the tightness.
Sometimes the reasons for the impeded tendon movement are unknown. However, trigger finger may be caused by a forceful or repeated movement of the fingers or thumbs, or prolonged gripping of vibrating machinery (such as a power tool). Sometimes other causes, such as rheumatoid arthritis, gout, or diabetes can be contributing factors.
An early symptom of trigger finger is usually soreness at the base of the finger or thumb.
In some cases, the finger may lock in either a bent or straight position. As the condition worsens, the finger may need to be straightened using the other hand.
The condition may be painful and can cause a swollen bump in the palm of the hand.
Your doctor will usually be able to diagnose trigger finger with a simple physical examination of your hand and fingers. In some cases, the finger may be locked in a bent position, it may be stiff, painful or swollen with a bump over the joint in the palm of the hand.