What is the carpal tunnel?
The carpal tunnel is a channel in your wrist. The bones of your wrist are arranged in a semi-circle that forms the sides and base of this channel. A tough band of tissue, known as the transverse carpal ligament, forms the roof.
The tendons that you use to flex your fingers and wrist pass through your carpal tunnel. Your carpal tunnel also surrounds your median nerve, which supplies feeling and controls muscles in your hand and thumb. If this nerve comes under pressure, it can lead to carpal tunnel syndrome.
Symptoms of carpal tunnel syndrome
Symptoms of carpal tunnel syndrome include:
- pain in your hand and wrist, which may spread to your forearm, upper arm and shoulder
- numb hands
- a tingling sensation
The weakness associated with carpal tunnel syndrome usually affects movements that involve your thumb, so you may find it difficult to grip things. Over time, your hand muscles can get weaker. And if your carpal tunnel syndrome is severe, your thumb muscles may start to waste away, or your median nerve may be permanently damaged.
Your symptoms may get better if you shake your wrist or change its position.
Both hands can be affected by carpal tunnel syndrome. You're most likely to feel symptoms in your thumb, index and middle fingers, and the side of your ring finger nearest to your thumb. At first, your symptoms may be mild but they may gradually get worse. And they might come and go. You can get symptoms at any time but often carpal tunnel syndrome is worse at night and may even wake you up.
If you have any of these symptoms, contact your GP for advice.
Causes of carpal tunnel syndrome
Carpal tunnel syndrome is caused by compression of the median nerve, which is in the wrist. There isn't much space in your carpal tunnel so any swelling can press on your median nerve, and cause the symptoms of carpal tunnel syndrome. There are lots of reasons why this may happen so it can be difficult to find a specific cause.
Some potential reasons include the following.
- Smaller carpal tunnels. Some people simply have smaller carpal tunnels. This means you’re more likely to develop problems if there’s pressure on the nerve.
- Weight. If you're overweight, you’re more likely to develop carpal tunnel syndrome.
- Age. The risk of getting carpal tunnel syndrome increases as you get older.
- Gender. Women are three times more likely than men to develop the condition, possibly because they naturally have smaller carpal tunnels.
- An injury. You may be more likely to develop carpal tunnel syndrome if you’ve injured your wrist, such as broken or sprained it.
- Other health conditions. You’re more likely to get carpal tunnel syndrome if you have another condition, such as diabetes, or an underactive thyroid.
- Hormones. Hormones may have something to do with carpal tunnel syndrome as some women develop it when they get pregnant or go through the menopause. See our FAQ: Can I take steroids if I'm pregnant? for more information about carpal tunnel syndrome and pregnancy.
- Repetitive actions. Doing certain actions can lead to carpal tunnel syndrome. If your work or hobbies include a lot of repetitive wrist actions, you may be more likely to get it, especially if you need to grip things tightly. If you work with vibrating tools, these can also make carpal tunnel syndrome more likely.
Diagnosis of carpal tunnel syndrome
Your GP will ask you about your symptoms and your medical history. They’ll examine you too by doing the following.
- Phalen test. Your GP will ask you to flex your wrists (or they may hold your wrist). If you get any pain or numbness within a minute, you may have carpal tunnel syndrome.
- Tinel test. In this test, your GP will tap or press on your median nerve in your wrist to see if you get any tingling in your fingers.
Your GP might be able to diagnose carpal tunnel syndrome just by examining you and talking to you. But you might need to have some tests, which may include the following.
- Nerve conduction test. Your GP may refer you for this test that can show if there’s any damage to your median nerve.
- Electromyography (EMG). You may need to have this test to see how well your muscles respond when a nerve is stimulated. This can indicate if you have any nerve damage. During the test, a technician will insert fine needles into your muscles, which will detect any natural electrical activity given off by them.
- Ultrasound. This uses sound waves to produce an image of the inside of your wrist. This will enable your doctor to look at the structure of the median nerve in your hand.
Resting your hands and wrists regularly can often relieve mild symptoms of carpal tunnel syndrome.
If you think repetitive hand movements are causing your problem, try to limit any activities that make your symptoms worse. It may help if you change the way you do these actions or reduce how often you do them. It may also help to rest more between bursts of activity.
Some people find that changing their mouse or keyboard shape can help, but there’s little evidence yet to prove this works. If you find your symptoms are worse at work, it might be worth having a chat with your employer about possible modifications to your workplace.
Treatment of carpal tunnel syndrome
Living with carpal tunnel syndrome can be painful at times.
There are treatments available, including carpal tunnel surgery. Carpal tunnel treatment helps to relieve your symptoms by reducing the pressure on your median nerve. As well as this carpal tunnel relief, it may also stop your condition from getting any worse.
If you only have mild symptoms, they may improve without any treatment after about six months, especially if you're pregnant or under 30.
Wrist splints for carpal tunnel syndrome
Wrist splints can help to keep your wrist straight and reduce pressure on the compressed nerve. This often relieves the symptoms of carpal tunnel syndrome.
Your doctor will usually advise you to wear wrist splints at night for several weeks or months. Your symptoms should start to improve within three months. You can wear splints during the day as well, but you may find that they get in the way as you go about your day.
Medicines for carpal tunnel syndrome
Medicines used to treat carpal tunnel syndrome include the following.
Steroid injections. Your doctor will inject this directly into your carpal tunnel. Although your pain may get a little worse for a couple of days after the injection, you should experience relief from symptoms after that. Some people find that their symptoms return after a few months, especially if they were serious to begin with. See our FAQ: How long will the injection’s effects last? for more information.
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen. These might help to relieve your pain.
Carpal tunnel surgery
If your symptoms are severe or other treatments haven’t worked for you, your GP may suggest you have carpal tunnel surgery (also called carpal tunnel release surgery). See Related information to find out what’s involved.
Carpal tunnel surgery is thought to work better than splinting at treating carpal tunnel syndrome, but doctors don’t know if it’s better than a steroid injection.
Other carpal tunnel syndrome treatments
Some people find that doing some hand and wrist exercises helps with carpal tunnel syndrome relief. But there isn’t much evidence to show that they work. More research is needed to see whether special hand exercises – called nerve and tendon gliding exercises – can help.
Some people find acupuncture helps to relieve the symptoms of carpal tunnel syndrome and some research suggests it works. But more evidence is needed before we know for sure if acupuncture is an effective carpal tunnel syndrome treatment.
There’s a small amount of evidence that yoga may help to relieve pain in some people with carpal tunnel syndrome. But again, more research is needed to know for sure.
If you decide to try a complementary therapy, check that your therapist is registered with a recognised organisation.
Our guide to living with carpal tunnel syndrome can help you understand what makes your symptoms better or worse and the treatment options available to you so you can manage your condition in a way that suits you.
FAQ: Do I have carpal tunnel syndrome or arthritis?
Some of the symptoms of osteoarthritis (‘wear and tear arthritis’) can be similar to those of carpal tunnel syndrome, but there are some key differences.
Both osteoarthritis and carpal tunnel syndrome can cause symptoms in the hand and wrist area. But with osteoarthritis you’re more likely to have swelling and/or stiffness of the joints around your wrist, especially in the morning. You may notice grating, cracking or popping sensations around your wrist when you move it. It may also hurt to lift heavy objects.
Carpal tunnel syndrome is more likely to cause a tingling sensation around the hand area – see the ‘Symptoms’ section above.
It is possible to have both carpal tunnel syndrome and osteoarthritis. If you think you may have either of these conditions, make an appointment to see your GP.
FAQ: I have carpal tunnel syndrome and I'm pregnant. Are steroids safe to use during pregnancy?
Corticosteroid injections are often prescribed to treat carpal tunnel syndrome. If you’re pregnant, you can still take them.
It's important to tell your GP if you think you might be pregnant as some medicines can harm your baby. But it’s not thought that taking a short course of these medicines during pregnancy will harm your baby.
You could try wearing a wrist splint first to see if it helps. But if you're in a lot of discomfort and other treatments haven't helped, your GP may suggest you have a steroid injection.
When you're pregnant, hormones you release can lead to fluid retention, which may cause swelling in your carpal tunnel and cause carpal tunnel syndrome. Your symptoms may get better once you’ve had your baby, often within six weeks.
FAQ: I had a steroid injection for my carpal tunnel syndrome. How long will the effects last and can I have another one if this wears off?
Some people find that their symptoms come back within a few months of having a corticosteroid injection for carpal tunnel syndrome. Having a second injection is unlikely to help.
Injections of corticosteroids can improve the symptoms of carpal tunnel syndrome in the short term. They work by reducing inflammation in your carpal tunnel and so relieve pressure on your median nerve. But some people find that their symptoms return after a few months.
You may be able to have further injections if your symptoms return and the first injection worked for you for a while. But there’s little evidence to show that this will give you any further relief.
If your symptoms return after one injection, your GP will probably refer you to see a specialist for further treatment.
FAQ: What’s the difference between carpal tunnel syndrome and repetitive strain injury?
Carpal tunnel syndrome is one of a number of conditions that can affect your arms and hands. One umbrella term for these types of disorders is repetitive strain injury (RSI).
There are lots of conditions that can affect your neck, shoulder, arm and hand. RSI is often used as an umbrella term to describe these. Another term used to describe them is overuse injury. These conditions are often very painful and can stop you carrying out daily activities and interfere with your work.
You may get carpal tunnel syndrome because of repetitive actions but there are many other causes too.
If you think you have carpal tunnel syndrome or another condition that’s causing RSI, have a chat with your employer. They may be able to give you workplace equipment and practices to help your symptoms.
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