Trigger finger causes include forceful use or repeated movement of the finger or the thumb, according to WebMD. Diabetes, gout and rheumatoid arthritis are additional causes. Using a firm grip to grasp an object such as a power tool for an extended period of time also causes trigger finger.
Trigger finger often occurs in industrial or factory workers, musicians, and farmers, who use their fingers and thumbs in repetitive movements, explains WebMD. Smokers may also develop trigger thumb as a result of the repeated striking of lighters. Women develop trigger finger more often than men, and people who are 40 to 60 years old are more prone to the condition than others.
The initial symptom of trigger finger is a sore feeling at the base of the affected finger or thumb, notes WebMD. A snapping noise or painful clicking when straightening or bending the finger is a common symptom of the condition. The catching sensation caused by trigger finger tends to loosen up with movement and become worse when resting the affected finger or thumb. In extreme cases, the finger or thumb may lock into a straight or bent position, requiring manual straightening using the unaffected hand.
A doctor diagnoses trigger finger with a physical examination, reports WebMD.