Overview
Trigger finger makes a finger get stuck in a bent position. It may straighten suddenly with a snap. The fingers most often affected are the ring finger and the thumb, but the condition can affect any finger.
Trigger finger happens when the tendon that controls that finger can't glide smoothly in the sheath that surrounds it. This may occur if part of the tendon sheath becomes swollen or if a small lump forms on the tendon.
The condition is most common in women over the age of 50. You may be at higher risk of trigger finger if you have diabetes, low thyroid function or rheumatoid arthritis.
Treatment of trigger finger can include splinting, steroid injections or surgery.
Symptoms
Symptoms of trigger finger may progress from mild to severe and include:
- Finger stiffness, particularly in the morning.
- A popping or clicking sensation as the finger moves.
- Tenderness or a bump in the palm at the base of the affected finger.
- Finger catching or locking in a bent position, which suddenly pops straight.
- Finger locked in a bent position.
Trigger finger can affect any finger, including the thumb. More than one finger may be affected at a time, and both hands might be involved. Triggering is usually worse in the morning.
Causes
Tendons are tough cords that attach muscle to bone. Each tendon is surrounded by a protective sheath. Trigger finger occurs when the affected finger's tendon sheath becomes irritated and swollen. This makes it harder for the tendon to glide through the sheath.
In most people, there's no explanation for why this irritation and swelling begins.
The constant back-and-forth irritation can cause a small lump of tissue to form on the tendon. This lump is called a nodule. The nodule can make it even harder for the tendon to glide smoothly.
Risk factors
Factors that put you at risk of developing trigger finger include:
- Repeated gripping. Occupations and hobbies that involve repetitive hand use and prolonged gripping may increase the risk of trigger finger.
- Certain health problems. People who have diabetes or rheumatoid arthritis are at higher risk of developing trigger finger.
- Your sex. Trigger finger is more common in women.
Complications
Trigger finger can make it harder to type, button a shirt or insert a key into a lock. It also can affect your ability to grip a steering wheel or grasp tools.