Carpal Tunnel Syndrome
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 thumbs pass through your carpal tunnel. So does your median nerve, which supplies feeling and controls muscles in your hand and thumb. If this nerve comes under pressure and is compressed, it can lead to the symptoms of 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, your upper arm and your shoulder
- numb hands
- a tingling sensation
Your carpal tunnel syndrome symptoms may feel better if you shake your wrist or change its position.
Both hands can be affected by carpal tunnel syndrome. Your hand will look normal, so you can’t see any physical signs. You’re most likely to feel symptoms in your hands, thumb and fingers. 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 carpal tunnel syndrome is often worse at night and may wake you up.
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 really serious, your thumb muscles may start to waste away, or your median nerve may be permanently damaged. But this doesn’t happen often – ask your doctor for more information.
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 a nerve in your wrist called the median nerve. Anything that reduces the space or increases the pressure in your carpal tunnel can potentially cause the symptoms of carpal tunnel syndrome.
There are lots of reasons why this may happen and it’s often difficult to determine whether there’s a specific cause of carpal tunnel syndrome. But the following can make you more likely to develop it.
- Smaller carpal tunnels: some people simply have smaller carpal tunnels than other people. This means you’re they’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. Most people who get it are over 30.
- Gender: women are three times more likely than men to develop carpal tunnel syndrome, 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 (for example, you may have broken or sprained it).
- Other health conditions: you’re more likely to get carpal tunnel syndrome if you have another condition such as diabetes, rheumatoid arthritis or an underactive thyroid.
- Hormones may have something to do with carpal tunnel syndrome as some women develop it when they get pregnant or at the start of the menopause. See our FAQs for more information about carpal tunnel syndrome and pregnancy.
- Repetitive 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 and may carry out the following tests.
- Phalen test: your GP will ask you to rest your elbows on a table and then 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: your GP will tap or press on your median nerve in your wrist to see if you get any tingling in your fingers.
- Median nerve compression test: your doctor will ask you to stretch out your elbow and hold your palm upwards. They’ll hold your wrist and press on carpal tunnel. If you feel symptoms within 30 seconds, it’s likely you have carpal tunnel syndrome.
Your GP may be able to diagnose carpal tunnel syndrome just by examining you and asking about your symptoms. But you might need to have some further tests, which may include the following.
- Nerve conduction test: this can show if there’s any damage to your median nerve.
- Ultrasound: this uses sound waves to produce an image of the inside of your wrist. This will enable your doctor to look at the area around your median nerve in your hand.
Self-help for 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.
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
There are carpal tunnel syndrome treatments available, including carpal tunnel surgery. Treatment helps to relieve your symptoms by reducing the pressure on your median nerve. As well as pain relief, this might 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 at least a month. 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 directly into your carpal tunnel can help with pain relief. Although your pain may get a little worse for a couple of days after the injection, you should get relief from symptoms after that. Some people find that their symptoms return within a year. See our FAQs for more information.
- Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen might help to relieve your pain and inflammation.
Carpal tunnel surgery
If your symptoms are severe or other treatments haven’t worked for you, your specialist doctor or surgeon may suggest you have carpal tunnel surgery (also called carpal tunnel release surgery). See our Related information to find out what’s involved.
Carpal tunnel surgery is thought to be more effective than splinting and steroid injections at treating carpal tunnel syndrome.
Other carpal tunnel syndrome treatments
Some people find that doing some hand and wrist exercises (physiotherapy) can help with carpal tunnel syndrome relief. But there isn’t much evidence to show that carpal tunnel syndrome exercises 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 on acupuncture as 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.