Which symptom describes trigger finger?

• A. Finger locking or catching with finger flexion
• B. Pain with extension only
• C. Numbness in the thumb
• D. Swelling at the DIP

Answer: (A)

Trigger finger happens when the flexor tendon that bends the finger becomes irritated and thickened as it slides through the pulley system, usually at the A1 pulley. This creates a narrowed passage, so as the finger moves into flexion the tendon can catch on the pulley. The result is a locking or catching sensation during flexion, and often the finger may suddenly pop into extension. That precise symptom—locking or catching with finger flexion—is the hallmark of trigger finger.

The other options don’t fit this pattern: pain that occurs only with extension suggests a different issue with the extensor mechanism or joint, numbness in the thumb points to median nerve compression like carpal tunnel, and swelling at the DIP junction isn't characteristic of trigger finger (it implies other joint or tendon problems).