Signs and symptoms of trigger finger may progress from mild to severe and include:

• Finger stiffness, particularly in the morning
• A popping or clicking sensation as you move your finger
• Tenderness or a bump (nodule) 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, which you are unable to straighten

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 more pronounced in the morning, while firmly grasping an object or when straightening your finger.

Tendons are fibrous 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 inflamed. This interferes with the normal gliding motion of the tendon through the sheath.

Prolonged irritation of the tendon sheath can produce scarring, thickening and the formation of bumps (nodules) in the tendon that impede the tendon's motion even more.

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 your 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.
• Carpal tunnel syndrome surgery. Trigger finger may be a complication associated with surgery for carpal tunnel syndrome surgery, especially during the first six months after surgery.