Trigger finger is a painful condition caused by swelling in the sheath where tendons move, preventing the tendons from gliding smoothly and causing the finger or thumb to catch and lock, especially when bending. Trigger finger is more common in people aged 45 and older, and in those with diabetes or rheumatoid arthritis.

Often affecting all fingers, but most commonly the thumb and ring finger, trigger finger, also known as trigger finger syndrome, is medically termed stenosing tenosynovitis.

Trigger finger is most common in women over 50, people with diabetes, those with hypothyroidism, and individuals suffering from rheumatoid arthritis. Symptoms most commonly include pain, but also swelling, clicking, snapping, and stiffness. Treatment often involves rest, splinting, and trigger finger exercises.