Trigger finger occurs when the cover over the cord that links muscles to bone becomes swollen and irritated. The cord, also known as a tendon, then can't move smoothly. Those most at risk include women, people with diabetes or arthritis, and people whose activities strain their hands.

Symptoms might get worse over time. Besides finger locking, symptoms include stiffness, a feeling of popping or clicking when the finger moves, and soreness in the affected finger. The condition is usually worse in the morning.

Treatment includes wearing a splint, taking medicine as a pill, cream or patch, and surgery.