Trigger finger is a condition that affects the tendons that control the fingers and thumb, causing pain, stiffness, and a sensation of locking or catching when you bend and straighten your finger. It happens when tendons, or their protective sheath, around your fingers or thumb swell up or thicken, making it hard for your affected digits to move smoothly. The swelling can be caused by several factors, including overuse or injury, medical conditions such as diabetes, low thyroid function, or rheumatoid arthritis, and age.

Symptoms of trigger finger include 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, and a finger locked in a bent position. Trigger finger can affect any finger, including the thumb, and more than one finger may be affected at a time, and both hands might be involved. Triggering is usually worse in the morning.

Treatment for trigger finger depends on how severe the symptoms are. Most of the time, rest is recommended, and avoiding activities that cause pain or discomfort. If the condition is severe, a steroid injection may be given to calm the irritation and swelling. In rare cases, surgery may be required to release the tendon sheath.