Stenosing tenosynovitis, commonly called trigger finger, is a condition where a finger catches or locks when you bend it. It happens when the tunnel that guides your finger’s tendon narrows, trapping the tendon and preventing smooth movement. The condition affects more than 3% of the general population, with the ring finger and thumb being the most common digits involved.
How the Finger Gets Stuck
Each finger has a long tendon that runs from your forearm into the fingertip, allowing you to curl your fingers into a fist. That tendon passes through a series of small tunnels called pulleys, which hold it close to the bone, much like the guides on a fishing rod keep the line in place. The first of these tunnels, known as the A1 pulley, sits right at the base of the finger where it meets the palm.
In a healthy hand, the tendon glides freely through the pulley during bending and straightening. In stenosing tenosynovitis, the tissue of the pulley thickens and stiffens, narrowing the opening. At the same time, the tendon sheath can swell. The result is friction: the tendon catches on the narrowed pulley as it tries to slide through. When the tendon finally pops past the obstruction, you feel (and sometimes hear) a snap, like pulling a trigger. That’s where the nickname comes from.
Under a microscope, the affected tissue shows distinctive changes. In one study of 38 surgical specimens, 84% had a dense, low-cell collagen buildup surrounding the tendon sheath. Cells in the area were producing excess hyaluronic acid, a substance that normally lubricates joints but in this case contributes to swelling that increases pressure under the pulley and worsens the narrowing over time.
What It Feels Like
The condition typically starts subtly. You might notice stiffness at the base of the affected finger, especially in the morning. A small, tender bump may form in the palm at the base of the finger. As it progresses, bending the finger produces a distinct catching sensation, sometimes with an audible click.
Clinicians grade the severity on a scale from 0 to 4. At the mildest level, the finger simply moves unevenly. At grade 2, the finger locks in a bent position but you can straighten it on your own. By grade 3, the finger locks and you need your other hand to physically push it straight, which is often painful. At grade 4, the finger is stuck in a fixed bent position and cannot be straightened at all. Many people first notice the problem when they wake up with a finger locked in their palm and have to pry it open with the opposite hand.
Who Gets It and Why
Stenosing tenosynovitis is most common in adults between 40 and 60, and women develop it roughly two to six times more often than men. It can affect any finger, but the ring finger, middle finger, and thumb are the usual targets. Some people develop it in multiple fingers at once or sequentially over time.
Diabetes is the single biggest medical risk factor. While the condition affects about 3% of the general population, prevalence jumps to between 5% and 20% among people with diabetes. The connection likely involves changes in how the body processes collagen and manages tissue repair, though the exact mechanism isn’t fully understood.
Repetitive gripping is a well-established occupational risk. Jobs and hobbies that involve prolonged forceful gripping or repeated finger movements, such as using hand tools, playing a musical instrument, or extensive manual labor, increase the likelihood of developing the condition. Rheumatoid arthritis, gout, and thyroid disorders are also associated with higher rates.
How It Differs From Similar Conditions
The catching and locking of a trigger finger can occasionally be confused with other hand problems, particularly Dupuytren’s contracture. Both can leave a finger stuck in a bent position, but they are fundamentally different. In stenosing tenosynovitis, the problem is a tendon trapped by a thickened pulley, and the finger locks and releases with a snap. In Dupuytren’s contracture, the tough tissue layer just beneath the palm skin thickens into cords that slowly pull the finger down into a permanent bend, with no catching or clicking involved. The progression is also different: Dupuytren’s develops over months or years without the intermittent locking that characterizes trigger finger.
Treatment Without Surgery
Mild to moderate cases often respond well to nonsurgical approaches. The first step is usually reducing the activity that aggravates it. Resting the hand and avoiding repetitive gripping gives the inflamed tissue a chance to settle down.
Night splinting is one of the more effective conservative options. Wearing a splint that holds the finger in a straight position while you sleep, typically for 8 to 12 hours per night, prevents the finger from curling and catching overnight. In one systematic review, 66% of participants showed improvement at a 52-week follow-up, and roughly half of the splinting group experienced complete resolution of their triggering. The sleeping-only wear group also reported no pain after treatment, making it a reasonable first-line approach for people who want to avoid injections.
Corticosteroid injections are the most common medical treatment. A small dose of anti-inflammatory medication is injected directly into the tendon sheath near the A1 pulley. A single injection resolves symptoms in a significant number of cases, and for people who get partial relief, a second injection can improve outcomes further. The effect may be temporary in some people, particularly those with diabetes, where recurrence rates tend to be higher.
When Surgery Is Needed
If splinting and injections don’t provide lasting relief, or if the finger is locked in a fixed position, surgical release is the next step. The goal is straightforward: cut the A1 pulley so the tendon can move freely again. This can be done two ways.
Open release involves a small incision in the palm. The surgeon directly visualizes the pulley and cuts it. It’s a reliable procedure with very low recurrence rates. Percutaneous release uses a needle inserted through the skin to divide the pulley without a traditional incision. Both techniques are effective, and in one large comparative study, neither group had any recurrences over roughly three and a half years of follow-up.
The practical difference between the two is recovery speed. With the percutaneous approach, half of patients experienced pain relief within two days and returned to work within three days. With open surgery, those milestones took about seven days and 15 days respectively. About 2.4% of percutaneous procedures need to be converted to an open release when the needle approach doesn’t fully divide the pulley.
What Recovery Looks Like
After surgical release, you’ll be asked to gently bend and straighten your fingers throughout the day to maintain flexibility and reduce swelling. For the first one to two weeks, you should avoid lifting anything heavier than one to two pounds and skip repetitive hand motions like typing, using a mouse, or chopping food.
If your job doesn’t require hand use, you may return to work within a day or two. If your work involves gripping, lifting, or repetitive movements, expect to take up to six weeks off. Full healing generally takes about six weeks, after which the finger typically moves freely without pain. Some people benefit from hand therapy to rebuild range of motion, strength, and grip, especially if the finger had been locked for a long time before surgery.