Repeated or forceful movements, rheumatoid arthritis, gout and diabetes can cause trigger finger, according to WebMD. The catching or locking that is called trigger finger occurs when a tendon that controls the finger is inflamed.
Tendons attach muscle to bone and are surrounded by a protective sheath. When either the sheath or tendon is injured or swollen, the tendon cannot glide freely through the sheath, according to Mayo Clinic, leaving the finger unable to bend or straighten. Nodules or bumps can form on the tendon, further impeding the smooth functioning of the finger.
Trigger finger can be treated by resting the joint for a few weeks though splinting and anti-inflammatory medications may be necessary, advises WebMD. Recovery varies but normally takes a few weeks.