Trigger finger

The tendons that bend the fingers and the thumb run along the palm side of the hand through tunnels of tough tissue that keep them close to the bone. At the mouth of each tunnel, in the palm, sits a firm band called the A1 pulley. If that mouth thickens, the tendon's surface roughens and swells, and it catches as it tries to slide through: the finger clicks, or locks bent and then snaps straight.

Why the tunnel thickens is often unclear. It is linked with:

• Being over 40, and it is commoner in women
• Diabetes, especially when insulin is needed, which can also make it more stubborn to treat; even so, most people with trigger finger do not have diabetes
• Rheumatoid arthritis, an underactive thyroid or gout, now and then
• A knock or injury to the hand, which occasionally seems to start it

There is little evidence that work causes it, though gripping at work, at home or in sport can make the pain worse. It can occur alongside carpal tunnel syndrome.

The ring finger, the middle finger and the thumb are the digits most often affected, and more than one can be. The signs may include:

• A click or a catch as the finger or thumb bends or straightens
• A digit that locks bent until you free it with the other hand, or that snaps straight on its own
• Pain and tenderness where the finger joins the palm, or on the palm side of the thumb
• Stiffness, worse on waking and after using the hand for tasks such as cooking, tools or sport

The pattern of catching or locking and an examination of the hand usually make the diagnosis: the tender spot at the base of the finger, the click as it moves, and sometimes a small nodule that slides with the tendon. Other causes of a finger that will not straighten, such as Dupuytren's contracture or arthritis in the finger joint, are part of what the examination rules out.

Point-of-care ultrasound, done by Dr Borukhson at the appointment, can show the thickened pulley and the tendon catching beneath it, and can guide an injection straight afterwards; the ultrasound clinic page has more on the scan.

Trigger finger is not harmful, but it can be very painful and gets in the way of using the hand. Some mild cases recover over a few weeks without treatment, and the options build up from there:

• Less of what brings it on. Easing off the hard gripping that sets off the pain gives the tendon a chance to settle, and simple painkillers can help meanwhile.
• A night splint. A small splint that holds the finger or thumb straight at night keeps the roughened part of the tendon inside the tunnel, where it can smooth over. A hand therapist can fit one; even a lollipop stick taped along the finger will do for a while.
• A steroid injection. A steroid injected into the tendon sheath relieves the pain and the triggering in about 70% of people, less often in people with diabetes. It can work within a few days or take several weeks, and a second injection sometimes helps. Afterwards the finger can be quite painful for a few days, and heavy use of the hand is best avoided for a few weeks. The risks are small: very occasionally the skin over the spot becomes thinner or paler. An ultrasound-guided injection shows the needle on screen as it reaches the sheath.
• A release. If the triggering persists, the tight mouth of the tunnel is opened. Most often this is a small operation through a short cut in the palm, under local anaesthetic, with the arm numbed or under a general anaesthetic, with care for the nerves beside the tunnel; light use of the hand is possible from the day of the operation, and the wound needs a small dressing for 10 to 14 days. Pain relief is usually quick; the scar may be red and tender for several weeks, and triggering seldom comes back. Some surgeons release the tunnel with a needle under local anaesthetic instead, though this suits only some fingers.

At this practice the assessment, the ultrasound scan and, where you and Dr Borukhson decide it is the right step, an ultrasound-guided injection can usually take place in the same visit, so you leave with a diagnosis and, where it is needed, the treatment begun.

You and Dr Borukhson settle the plan together.

While the tendon settles, small changes in how you use the hand often help:

• Cut down on the gripping that brings it on, and use gadgets that make hard tasks easier, such as a jar opener
• Break up long spells of gripping, and do not grip things too tightly
• Wear the night splint as advised
• Keep the finger moving gently through its range during the day, rather than forcing it when it catches
• If you have diabetes, good control of your blood sugar may help the finger recover

A finger that has been locked bent for a long time can stiffen and become harder to free, which is why a finger fixed bent goes to a GP within days, under When to seek help.

Trigger finger is not dangerous, and most trigger finger problems are for a GP or a booked assessment. For the pictures that need more, the lists below give the route for each; among them are a finger or palm gone hot, red or very painful, which can be an infection, more so after a cut or a bite; a fever and feeling very unwell, which can be sepsis; an injured hand; a hand or arm that loses strength or feeling all of a sudden; and tingling that has come on together with neck pain.

Treat any of these as a 999 or A&E emergency: call 999 and do not drive yourself to A&E.

• Severe illness with suspected sepsis: a high fever with shaking, confusion, rapid breathing, or feeling dramatically worse over hours
• With a fever or feeling unwell, a rash that does not fade when you press it, a stiff neck with eyes that cannot bear bright light, or skin, lips or tongue turning blue, grey, pale or blotchy, since these can be signs of meningitis or sepsis; on black or brown skin the rash and the change of colour may be easier to see on the palms of the hands or the soles of the feet
• A joint you cannot put weight on or move, or that has moved out of place, or, after a fall or injury, very bad pain or any tingling or numbness
• After an injury, a crack heard as it happened, or skin around it that has turned blue, grey or cold, since these can be signs of a broken bone
• Sudden weakness or numbness on one side, a drooping face or difficulty speaking, a sudden severe headache, sudden confusion or a seizure, or sudden loss of vision, any of which can be a stroke, even if it stops after a short time, and a hand or an arm that has suddenly gone weak or numb, with no injury behind it, is one of these signs
• An eye that suddenly and completely loses its sight
• Lips, mouth, throat or tongue that suddenly swell, a throat that feels tight, very fast breathing or a struggle to breathe or to swallow, skin, tongue or lips turning blue, grey or pale (on black or brown skin this may be easier to see on the palms of the hands or the soles of the feet), becoming suddenly very confused, drowsy or dizzy, or fainting and not being able to be woken, since this can be a severe allergic reaction, anaphylaxis, which can follow a dose of any medicine

Any of these needs an assessment that is urgent, on the same day, from your GP or NHS 111:

• A joint that is hot and swollen, with a fever or feeling unwell, since an infected joint has to be ruled out at once, at A&E or through NHS 111
• A joint that has become hot and very swollen suddenly, or is worsening quickly, even without a fever, since an infected joint does not always announce itself with one
• Joint pain with a fever, or feeling hot, cold or shivery, or generally unwell, since an infection in or around a joint has to be found the same day
• A lump, a finger or the palm that has turned very painful, hot or red, or hand pain with feeling hot, cold or shivery, since an infection in the hand can show itself this way and has to be found the same day, at A&E or through NHS 111 if a fever comes with it or you feel ill, short of the signs that follow; a lump, or the skin of a finger or the palm, turned hot or red, with a very high temperature or feeling hot, cold or shivery, a fast heartbeat or fast breathing, purple patches on the skin, which may be less obvious on black or brown skin, feeling dizzy or faint, confusion, or skin that is cold, clammy or pale, is a 999 or A&E emergency: call 999 and do not drive yourself to A&E
• Tingling in a hand, or numbness or weakness there that has come on gradually, with neck pain, since a nerve trapped at the neck can bring it on, and seeing someone that day tells it apart from pressure on the spinal cord, as our neck pain guide explains

See a GP if a finger or thumb keeps catching or locking and is not getting better, if it is stopping you doing your usual daily activities, and, if you have diabetes, whatever the timescale. Tingling or a loss of feeling that comes and goes, with no injury and no neck pain, is for a GP as well. See a GP within days if a finger is fixed bent and will not straighten even with your other hand, since a digit left locked can stiffen: with no injury behind it, that is the tendon catching, not the joint that cannot be moved in the first list, while a finger held bent that is swollen, hot, red or very painful should be seen that same day by a GP or through NHS 111, as it can mean an infection. See a GP within days, too, if numbness no longer clears, you keep dropping things, the hand has slowly grown weak or the muscle at the base of the thumb is wasting. Morning stiffness of the hands lasting over half an hour, a whole finger that has swollen, or a hand that is warm, swollen and stiff calls for a GP within days, as an inflammatory arthritis can begin like this. Where neck pain comes with the nerve signs, they move to the same-day list; sudden weakness or numbness, or numbness after an injury, moves to the first list. No referral is needed to be seen here; next-working-day appointments can almost always be arranged, and same-day appointments are sometimes possible. A bite wound on the hand or finger that is large or deep, or that will not stop bleeding, is a 999 or A&E emergency: call 999 and do not drive yourself to A&E. Any other bite on the hand or finger needs NHS 111 the same day. After an injury, a hand or wrist knocked out of shape, a finger bent at an odd angle, or a cut through which bone can be seen is a 999 or A&E emergency; an injury to the hand that stops short of those and of the signs in the first list is one for NHS 111, which can tell you whether a bone needs an X-ray. If you cannot tell how urgent something is, asking is never a mistake.

Most trigger fingers respond well to treatment, and treating one before it stays locked can help stop it stiffening. One visit can confirm it, look for anything that sits alongside it, such as carpal tunnel syndrome, and start the treatment. If a finger or thumb clicks or locks, it is worth arranging.

What happens at an assessment for trigger finger?

Your description and a look at the hand are usually enough: the click or lock as the digit bends, a tender spot where the finger meets the palm, or on the palm side of the thumb, and sometimes a small nodule there that moves with the tendon. An ultrasound, usually in the same visit, can show the tendon catching at the mouth of its tunnel, and can help tell trigger finger from other causes of a stiff or bent finger.

Does trigger finger ever settle by itself?

Sometimes: a mild case can clear up within weeks, particularly if you ease off the gripping that brings it on, and a small night splint keeping the finger straight can help the tendon settle. If the finger keeps catching, locks often, or the symptoms are stopping you doing your usual things, see a GP or book an assessment.

Does an injection stop the triggering?

In most people: a steroid injection into the tendon sheath relieves the pain and the triggering in about 70% of people, though less often in people with diabetes. It can help within a few days or take several weeks, and the relief can wear off. A second injection is sometimes worth trying; if the triggering persists after that, a small operation to release the tunnel is usually the answer.

Can it be assessed and treated in one visit?

Usually, yes. The examination, the ultrasound scan and, if it is agreed with Dr Borukhson as the right step, an injection guided into the sheath can take place in the same appointment. No referral is needed, and next-working-day appointments can almost always be arranged.

Is trigger finger a form of carpal tunnel syndrome?

No, though the two can occur together. Trigger finger is a tendon that catches, so the digit clicks or locks. Carpal tunnel syndrome is a nerve squeezed at the wrist, so the thumb and fingers tingle or turn numb, often at night. Examining the hand usually separates them, with a scan where it helps, and both can be treated at the same time.