Trigger Thumb

What is trigger thumb?

Trigger thumb means your child’s thumb pops, clicks or catches when they try to straighten it. Their thumb may lock in a bent or straight position. If the thumb locks, your child can move it using their other hand. (Or you can move it for them.) But they can’t move the locked thumb using their thumb muscles.

In children, trigger thumb usually happens between the ages of 1 and 3 years old. It’s not thought to be due to injury or other medical problems.

Most children with trigger thumb have it in only 1 hand. About 1 child in 3 has it in both hands.

How does trigger thumb happen?

The muscle that bends the tip of the thumb is called flexor pollicis longus (FLEX-er PAHL-i-sis LONG-us). This muscle starts in your child’s forearm. Near the wrist, the muscle turns into . The tendon runs along the palm side of your child’s thumb and connects to the bone in the tip of the thumb.

When your child moves their thumb, this tendon should glide smoothly inside a wrapping called a tendon sheath. Near the base of the thumb, a tough band (ligament) crosses the tendon and tendon sheath, acting like a pulley. Doctors call this the A1 pulley.

Trigger thumb happens when the tendon swells, forming a bump (nodule) near the A1 pulley. The nodule gets stuck at the pulley, so the tendon cannot glide inside the sheath. You may be able to feel this bump on your child’s palm at the base of their thumb.

Triggering can happen in fingers too. This is a different and more complex problem.

Why choose Seattle Children’s for trigger thumb treatment?

Trigger thumb is among the most common conditions we treat in Seattle Children’s Hand and Upper Extremity Program. Each year we see many children with this condition in our clinics. Our team is experienced in the range of treatment options for trigger thumb. We create a treatment plan custom-made for your child to get the best results for them.

  • The hand experts you need are here
    • Your child’s team includes doctors, surgeons, and nurses from Orthopedics and Sports Medicine.
    • For many children, treatment begins with observation, or watching over time to see if the trigger thumb gets better on its own. Often it does.
    • If trigger thumb doesn’t get better by age 4 or if it is painful or harms your child’s function, your child may need surgery to release the A1 pulley. Our surgeons are experienced at doing this type of surgery in children. We have surgeons with expanded fellowship training in upper extremity surgery.
  • Care from birth through young adulthood
    • We specialize in caring for kids. This means our experts have the knowledge, training and skills to treat the youngest patients, including babies and young children with trigger thumb. At Seattle Children’s, your child’s team has special training in the medical, surgical, emotional and social needs of young people.
    • Babies and children are still developing. When we evaluate your child’s condition, plan their treatment and provide their care, we carefully consider their growth. We think about how growth may affect your child’s hands and thumbs over time. We also consider how their condition and treatment may affect the rest of their development and health.
  • Support for you and your family
    • We know it can be stressful to have a child with a hand condition and to find the treatment they need. Everyone at Seattle Children’s works to make your experience here as easy as we can on your whole family.
    • Your child’s team does more than plan and provide care for your child. We also make sure you and your child understand your child’s condition and treatment options.
    • Seattle Children’s supports your family with a range of resources. Our Child Life specialists, Family Resource Center and Guest Services are here to help.

What are the symptoms of trigger thumb?

If your child has trigger thumb, they will have 1 or both of these symptoms:

  • Popping, clicking or catching when they move their thumb
  • Thumb locked in a bent or straight position

Your child may also have these symptoms:

  • Pain and swelling in their thumb, usually near the base
  • Bump on the palm side of their thumb, near the base

How is trigger thumb diagnosed?

Doctors can diagnose trigger thumb by asking about your child’s symptoms and doing a physical exam.

If your child seems to have trigger thumb, the doctor will check to make sure they do not have some other problem, like a broken bone or a that’s out of place (dislocated).

The doctor will also check for signs of broader health conditions that may affect the hands, like cerebral palsy or arthrogryposis. Most children with trigger thumb do not have any other condition.

How is trigger thumb treated?

Trigger thumb may get better on its own. Some children with trigger thumb need surgery so their thumb can move freely.


Trigger thumb in children often gets better over time without any special care. So, treatment usually begins with observation, or watching to see if the condition improves. The doctor will also consider if your child’s trigger thumb causes pain or if it gets in the way of your child using their hand for typical activities.


If trigger thumb doesn’t get better by age 4 or if it is painful or harms your child’s function, your child may need a  called trigger thumb release or A1 pulley release.

The surgeon makes a small cut (incision) on your child’s palm in the crease of skin at the base of the thumb. Then the surgeon cuts through the A1 pulley. This takes pressure off the tendon and allows it to glide smoothly. (The surgeon doesn’t cut into the tendon or remove the nodule.)

After surgery, your child will need a cast for 2 weeks to protect and stretch their thumb while it heals. Trigger thumb rarely comes back, and children rarely need any other treatment for it. You can expect your child to regain typical use of their thumb.

Contact Us

Contact Orthopedics and Sports Medicine at 206-987-2109 for an appointment, a second opinion or more information.

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