Trigger finger, also known as stenosing tenosynovitis, is a condition that makes it difficult to bend or straighten one or more fingers or the thumb. This happens due to inflammation and thickening of the tendon or its sheath (the tendon’s protective covering), which can cause pain, stiffness, a clicking or popping sensation, and sometimes locking of the affected digit in a bent position.

Trigger finger is one of the most common causes of hand pain and disability in adults, with a reported prevalence of about 2% to 3% in the general population. It is more common in women than in men, and typically occurs in people in their 40s or 50s, though it can develop at any age. In children, the condition is equally common in boys and girls.

Trigger finger can be managed effectively with a range of treatments, and most people experience significant improvement or complete resolution of symptoms.

Normally, flexor tendons—cord-like structures that connect muscles in the forearm to the bones of the fingers and thumb—move easily within the tendon sheath as during bending and straightening of the fingers and thumb. Bands of tissue called pulleys hold the tendons close to the bones, allowing for smooth, pain-free movement.

Trigger finger is a condition in which one or more fingers or the thumb become difficult to bend or straighten because the tendon sheath or the A1 pulley (the pulley at the base of the finger or thumb) becomes thickened, inflamed, or narrowed. This makes it harder for the tendon to glide through the sheath, and a small nodule may form on the tendon itself. As a result, the tendon can catch or lock when moving the finger or thumb, causing a clicking or popping sensation, pain, and sometimes a digit that is stuck in a bent position. The condition can develop gradually or suddenly, and in severe cases, the finger or thumb may remain locked and require help to straighten.

Trigger finger can affect any finger or the thumb, and it may involve more than one finger. It can affect fingers on one hand or both hands. In children, it most often affects the thumb. In infants and young children, “trigger thumb” (trigger finger affecting the thumb) and trigger finger in older, school‑age children are considered separate from adult trigger finger; many cases get better on their own, but if they do not, surgical release (a surgery to release the tight tendon sheath) is often needed.

The exact cause of trigger finger is not fully understood. In most cases, the condition develops without a clear reason, though several factors are thought to contribute.

Trigger finger is more likely to develop in people with certain medical conditions, such as diabetes, rheumatoid arthritis, gout, amyloidosis, hypothyroidism, and carpal tunnel syndrome. In children, the condition is believed to be related to a developmental mismatch between the size of the tendon and its sheath, especially in the thumb. In rare cases, an injury or the presence of growths, such as cysts or tumors, that can press on the tendon may also play a role.

The condition has been linked to repeated or forceful use of the fingers and thumb, which could lead to inflammation and thickening of the tendon sheath or the A1 pulley, making it harder for the tendon to glide smoothly. Over time, this can result in the formation of a nodule on the tendon, which further aggravates the problem.

Risk factors for trigger finger include:

• Age over 40 or 45 years
• Female sex
• Certain inflammatory conditions such as rheumatoid arthritis and gout
• Certain endocrine conditions such as diabetes and hypothyroidism (underactive thyroid)
• Amyloidosis
• Carpal tunnel syndrome
• Repetitive or forceful hand use or gripping activities
• Previous hand injury
• Presence of cysts or tumors in the hand that may press on the tendon
• Mucopolysaccharidosis (an inherited metabolic disease)

Symptoms of trigger finger may include:

• Pain at the base of the affected finger or thumb
• Stiffness in the finger or thumb, especially in the morning
• A clicking, popping, or snapping sensation when moving the finger or thumb
• A tender lump or nodule in the palm at the base of the affected finger or thumb
• Locking or catching of the finger or thumb in a bent position
• Difficulty straightening the finger or thumb
• Swelling of the affected finger
• Loss of full range of motion of the affected finger or thumb
• The finger or thumb suddenly popping straight after being stuck

In some cases, the finger or thumb may become stuck in a bent position and may require help from the other hand to straighten it. In more severe cases, straightening the affected finger or thumb requires assistance from a health care provider.

To diagnose trigger finger, your doctor will review your medical history, conduct a physical exam, and, in some cases, may order one or more diagnostic tests.

Your doctor will ask you about your symptoms, such as pain, stiffness, clicking, or locking of the finger or thumb, and whether these symptoms are worse at certain times of day or after specific activities. They may also ask about any underlying medical conditions, such as diabetes or rheumatoid arthritis, and any history of hand injuries or repetitive hand use.

During the physical exam, your doctor will check for tenderness, swelling, or a lump at the base of the affected finger or thumb, and may feel for a nodule or thickening along the tendon. They will observe your ability to bend and straighten your finger or thumb, looking for signs of catching, locking, or loss of motion. The doctor may also ask you to open and close your hand to see if the triggering or locking can be reproduced.

Additional tests are rarely needed to make the diagnosis, but in some cases, your doctor may order the following:

• Ultrasound: This imaging test can show thickening of the tendon or pulley, inflammation, or the presence of a nodule, and can help confirm the diagnosis or rule out other conditions.
• X-rays: These may be used to rule out other causes of finger pain or stiffness, such as fractures or arthritis.
  

Trigger finger can often be managed successfully with a range of treatments. The choice of treatment depends on the severity of symptoms, how long they have been present, and whether other medical conditions are involved. In some cases, mild trigger finger may improve on its own without treatment.

The main treatments for trigger finger include:

• Rest and activity modification: Avoiding activities that make symptoms worse can help reduce inflammation and allow the tendon to heal.
• Splinting: Wearing a splint, often at night, keeps the affected finger or thumb in a straight position and limits movement, which can help decrease pain and improve motion. Sometimes, taping the affected finger to adjacent healthy fingers can have the same effect as splinting.
• Nonsteroidal anti-inflammatory drugs (NSAIDs): These medications can help relieve pain and reduce inflammation.
• Stretching and hand therapy: Gentle stretching exercises and, in some cases, supervised hand therapy can help improve range of motion and decrease stiffness.
• Steroid injections: Injecting a corticosteroid into the tendon sheath at the base of the affected finger or thumb can reduce swelling and allow the tendon to move more freely. This treatment is effective for many people, though it may be less effective in those with diabetes or multiple affected fingers. If the injection doesn’t provide complete relief, a second injection may be given. Steroid injections provide lasting symptom relief and allow people to avoid surgery in about 70% to 80% of cases.
• Surgery: If other treatments do not relieve symptoms, or if the finger or thumb is locked in a bent position, a minor surgical procedure may be recommended. The most common surgery is release of the A1 pulley, which allows the tendon to glide smoothly again. In this procedure, the surgeon cuts the A1 pulley, allowing the tendon to move freely. A1 pulley release surgery has a high success rate. The vast majority of trigger finger release surgeries are performed while the patient is awake, avoiding the risks of general anesthesia.

People with trigger finger may be at increased risk for certain complications, including:

• Permanent loss of range of motion: If left untreated, the affected finger or thumb may become permanently stuck in a bent position.
• Joint contracture: The finger or thumb may develop abnormal tightening of tissues, making it difficult or impossible to straighten.
• Chronic pain or stiffness: Ongoing discomfort or limited movement may persist, even after treatment.

In many cases, trigger finger responds well to conservative treatments such as rest, splinting, and steroid injections, with most people experiencing significant improvement or complete resolution of symptoms. Some mild cases may even improve on their own without treatment.

For those who require surgery, the procedure is usually highly effective, and most people regain normal hand function and return to their usual activities within a few weeks. People with diabetes or multiple affected fingers may have a slightly lower chance of complete recovery.

This article was medically reviewed by Xuan Luo, MD, a Yale Medicine hand, shoulder, and elbow surgeon who cares for patients of all ages.