Trigger finger is usually caused by swelling of 1 of the tendons that run along your fingers and thumbs, although the exact reason why this occurs is not fully understood.

The swelling makes it difficult for the affected tendon to slide through its membrane (tendon sheath), causing the pain and stiffness associated with trigger finger.

The swelling can cause a section of the tendon to become bunched into a small lump (nodule) at the base of the affected finger or thumb.

If a nodule forms, the tendon can get trapped in the tendon sheath, causing the affected finger or thumb to become temporarily stuck in a bent position. The affected tendon may then suddenly break free, releasing your finger like the release of a trigger.

Who's most at risk?

The exact cause of trigger finger is not fully understood. However, you're more at risk of developing trigger finger if:

• you're female (trigger finger is more common in women than men)
• you're in your 40s or 50s (trigger finger is more common in this age group)
• you've had a previous hand injury – trigger finger may be more likely to develop after injuring the base of your finger or palm

Other health conditions

You may also be more likely to develop trigger finger if you have any of the following conditions:

• diabetes – a lifelong condition that causes a person's blood sugar level to become too high
• rheumatoid arthritis – a long-term condition caused by a problem with your immune system (the body's natural defence system), resulting in pain and stiffness in your joints
• gout – a type of arthritis where crystals of sodium urate form inside and around joints causing them to become inflamed (swollen)
• amyloidosis – a condition where an abnormal protein called amyloid builds up in organs, such as your liver
• underactive thyroid – where your body does not produce enough of certain hormones
• carpal tunnel syndrome – a condition that affects the nerves in your wrist, causing pain and tingling
• Dupuytren's contracture – a condition that causes 1 or more fingers to bend into the palm of your hand
• De Quervain's disease – a condition that affects the tendons in your thumb, causing pain in your wrist

The treatment for trigger finger depends on the severity of your symptoms and how long you've had them.

Sometimes, trigger finger gets better without treatment, so your GP may recommend avoiding activities that cause the pain to see if this helps relieve your symptoms. 

Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may also be helpful in relieving any pain.

Splinting

Strapping your affected finger or thumb to a plastic splint can ease your symptoms by stopping your finger moving. If your finger is particularly stiff in the morning, it may help to use a splint overnight. Your GP can advise you about how long you need to wear the splint for.

Using a splint can be helpful for some people, but it's generally less effective than the treatments described below, particularly in the long-term.

Corticosteroid injections

Corticosteroids are medicines that can be used to reduce swelling. In cases of trigger finger, liquid corticosteroids are injected into the tendon sheath (the membrane that the tendon slides through), at the base of the affected finger or thumb.

Corticosteroids are thought to work by reducing swelling of the tendon, allowing the tendon to move freely again. This can sometimes happen within a few days of having the injection, but it usually takes a few weeks.

It's estimated that corticosteroid injections are an effective treatment for 50 to 70% of people with trigger finger. However, they're generally less effective in people with certain underlying health conditions, such as diabetes and rheumatoid arthritis.

A corticosteroid injection can permanently improve trigger finger but, in some cases, the problem can return after treatment. You can have a second injection if the effect wears off, but it's often less effective than the first injection.

The risks of corticosteroid injections for trigger finger are small. Very occasionally, it causes some thinning or colour change in the skin at the site of injection. There's also a very small risk of infection.

Surgery

Surgery may be recommended if the above treatments do not work or are unsuitable. The surgeon will cut through the affected section of the tendon sheath so that your tendon can move freely again.

Whether surgery is recommended will depend on considerations such as the amount of pain you're in, whether it's associated with other medical problems, such as rheumatoid arthritis, and how much it's affecting your life.

In most cases, trigger finger is a nuisance rather than a serious condition. However, if it is not treated, the affected finger or thumb may become permanently stuck in a bent position or, less commonly, in a straightened position. This can make carrying out everyday tasks difficult.

Surgery for trigger finger is effective and it's rare for the problem to return in the treated finger or thumb. However, you may need to take some time off work and there's a risk of complications (see below).

The operation takes around 20 minutes, and you will not need to stay in hospital overnight. The procedure is usually carried out under local anaesthetic, so you'll be awake but unable to feel any pain in your hand.

The 2 types of surgery for trigger finger are:

• open trigger finger release surgery
• percutaneous trigger finger release surgery

If you have rheumatoid arthritis, these types of surgery may not be recommended because they can cause your finger to drift sideways. Instead, a procedure known as a tenosynovectomy may be necessary. This involves removing part of the tendon sheath to allow the tendon to move again.

Open trigger finger release surgery

If you have open trigger finger release surgery, the surgeon will give you an injection of local anaesthetic into the palm of your hand. 

A small incision will be made in the palm of your hand along one of the natural creases, which may mean the scar will be less noticeable. The surgeon will carefully cut through the tendon sheath to make it wider. The wound will then be closed with stitches and covered with a light bandage.

Percutaneous trigger finger release surgery

Percutaneous means "through the skin". As with open surgery, the surgeon will inject your hand with a local anaesthetic. However, instead of making an incision in your palm, a needle will be inserted into the base of the affected finger and used to slice through the ligament to get to the tendon.

As percutaneous surgery does not involve making an incision, you will not have a wound or scar. However, the procedure is slightly more risky than open surgery and may be less effective at resolving the problem. Important nerves and arteries are very close to the tendon sheath and can easily be damaged. For this reason, open surgery is usually the preferred method.

Recovering from surgery

After the procedure, you should be able to move your finger straight away. The dressings can usually be removed after a few days to make movement easier, and full movement should return within 2 weeks.

If you've had open surgery, your palm may feel sore immediately after the procedure, but any discomfort should pass within 2 weeks.

You can start driving again as soon as you feel it's safe for you to drive, which is usually after 3 to 5 days. You may be able to write and use a computer immediately.

You can play sports after around 2 or 3 weeks, once your wound has healed and you can grip again.

When you can return to work will depend on your job. If you have a desk job or a role that involves light manual duties, you may not need any time off work. If your job involves manual labour, you may need up to 4 weeks off.

If you've had surgery on several fingers, your recovery period may be longer.

If you've had percutaneous surgery rather than open trigger finger release surgery, your recovery period may be shorter because you will not have a wound on your palm.

Caring for your wound

If you've had open surgery, your surgeon should advise you about how to care for the wound in your palm. Washing it with mild soap and warm water is usually all that's required.

If you have stitches, you'll be told if you need to return to hospital to have them removed. Some stitches are dissolvable and will disappear on their own in around 3 weeks.

After your wound has healed, you may be left with a small scar running along your palm, where the incision was made. Read more about scars.

Hand therapy

If your finger was quite stiff before surgery, you may need specialised hand therapy after your operation to loosen it. Discuss this with your surgeon before the operation. The types of therapy you may need include:

• physiotherapy – where manipulation, massage and exercises are used to improve the movement and function of your hand
• occupational therapy – if you're struggling with everyday tasks and activities, either at work or at home, an occupational therapist will be able to give you practical support to make those tasks easier

Complications of surgery

Trigger finger release surgery is a safe procedure. However, as with any type of surgery, there are some risks. Complications are rare, but could include:

• infection
• stiffness or pain in the finger
• a tender scar
• nerve damage (if a nerve is damaged during surgery, you may never recover the full sensation in the affected area)
• tendon bowstringing, where the tendon is in the wrong position
• complex regional pain syndrome (CRPS), which causes pain and swelling in your hand after surgery – this usually resolves itself after a few months, but there can be permanent problems

Before your operation, ask your surgeon to discuss the possible complications and risks with you in more detail.

Treating children with trigger finger

Trigger finger in children will often improve without treatment as the child gets older, although splinting and simple hand stretches may help.

Steroid injections are not usually used in children, but surgery under general anaesthetic can be carried out if necessary.