(See also Overview of Hand Disorders Overview of Hand Disorders Hand and finger disorders include ganglia, deformities, disorders related to nerves or blood vessels, osteoarthritis, trigger finger, Kienböck disease, and infections. Some other disorders that... read more .)
The cause of trigger finger is unknown. Trigger finger is common among people with rheumatoid arthritis Rheumatoid Arthritis (RA) Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more or diabetes Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Urination and thirst are... read more . Repetitive use of the hands (as may occur from using heavy gardening shears) makes trigger finger more likely to develop.
In trigger finger, a finger becomes locked in a bent position. The finger locks when one of the tendons Tendons and Bursae Tendons are tough bands of connective tissue made up mostly of a rigid protein called collagen. Tendons firmly attach each end of a muscle to a bone. They are often located within sheaths, which... read more that flex the finger becomes inflamed and swollen, often with a noticeable round, raised area (nodule) in the palm. The inflammation and swelling may cause pain in the palm and in the base of the finger, especially when the finger is flexed and extended.
Normally, the tendon moves smoothly in and out of its surrounding sheath as the finger straightens and bends. In trigger finger, the inflamed tendon can move out of the sheath as the finger bends. However, when the tendon is very swollen, it cannot easily move back in as the finger tries to straighten, and therefore the finger locks. To straighten the finger, a person must pull on the finger to force the swollen area into the sheath—causing a sudden release and popping sensation similar to that felt when pulling a trigger.
A doctor makes the diagnosis of trigger finger by examining the hand and finger.
In people with trigger finger, splinting, moist heat, and nonsteroidal anti-inflammatory drugs (NSAIDs Nonsteroidal Anti-Inflammatory Drugs In some cases, treating the underlying disorder eliminates or minimizes the pain. For example, setting a broken bone in a cast or giving antibiotics for an infected joint helps reduce pain.... read more ) can help people who have swelling and pain.
Sometimes a corticosteroid Corticosteroids Rheumatoid arthritis is an inflammatory arthritis in which joints, usually including those of the hands and feet, are inflamed, resulting in swelling, pain, and often destruction of joints.... read more and a local anesthetic are injected into the tendon sheath and, along with splinting, may provide safe and temporary but rapid relief of pain and triggering.
Surgery is commonly needed to treat chronic trigger finger.