Carpal tunnel syndrome is a condition in which a nerve in your wrist comes under pressure. This causes pain, tingling or weakness, mainly in your forearm and hand.
Your 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 many muscles in your hand and thumb. If this nerve comes under pressure, it can lead to carpal tunnel syndrome.
Carpal tunnel syndrome is more common in women than men. It affects about three in 100 men and four to five in 100 women at some point in their life. People aged between 45 and 65 are more commonly affected and it’s rare for it to affect children.
If you have carpal tunnel syndrome, you may have symptoms including:
These symptoms mainly affect your wrist and hand. You're most likely to get these symptoms in your thumb, index and middle fingers, and the side of your ring finger nearest to your thumb. You may also get aching or pain in your forearm, upper arm and shoulder.
It’s common for both hands to be affected. If so, you will probably notice symptoms in your dominant hand first.
Any weakness usually occurs in movements involving your thumb. You may find it difficult to grip things, or have trouble carrying out actions such as fastening buttons. Over time, your hand muscles may continue to get weaker. If you have severe, long-lasting carpal tunnel syndrome, your thumb muscles may start to waste away or your median nerve may become permanently damaged.
It’s possible that your hand will change colour and the skin on your hand may become dry. You may also feel as though your fingers or hands are swollen, even though they don’t look it. If you have numbness, you may not be able to tell the different between hot and cold when you touch objects.
At first, your symptoms may be mild or last for only short periods of time. They can happen at any time but often carpal tunnel syndrome is worse at night and may cause you to wake up. Your symptoms may get better if you shake your wrist or change its position.
If you have any of these or similar symptoms, see your GP for advice.
There isn't much space in your carpal tunnel so any swelling there can press on your median nerve, causing the symptoms of carpal tunnel syndrome. There are many reasons why this may happen, but often it’s not possible to find a specific cause.
Some people simply have smaller carpal tunnels, which makes them more at risk of developing carpal tunnel syndrome. It’s thought that this tendency may run in families. Therefore, you may have a smaller carpal tunnel because other members of your family do. This means you will be more likely to develop problems if there is increased pressure on the nerve.
You're more likely to develop the condition if you're overweight. The condition is also more common as you get older. More women than men develop the condition, possibly because women naturally have smaller carpal tunnels.
You may be more likely to develop carpal tunnel syndrome if you have had an injury to your wrist such as a break or sprain, or have certain diseases, including:
It’s possible that hormones have something to do with carpal tunnel syndrome as some women develop the condition during pregnancy or the menopause. Hormones released during pregnancy can result in fluid retention in the tissues and increased pressure in your carpal tunnel. See our frequently asked questions for more information.
Carrying out certain actions may lead to carpal tunnel syndrome. People whose work or hobbies include a lot of repetitive wrist actions may be more likely to get it, especially if they need to use a forceful grip. Working with vibrating tools can also make carpal tunnel syndrome more likely. At the moment, there’s no strong evidence that working with a computer mouse or keyboards causes this condition.
Your GP will ask you about your symptoms and examine you. He or she may also ask you about your medical history and might be able to diagnose carpal tunnel syndrome just by examining you and talking to you. He or she may test the feeling on the skin of your hand to see if there is any numbness. He or she may also ask you to move your fingers and thumb to test for muscle weakness.
There are some tests that can help diagnose carpal tunnel syndrome, for example, the 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 one minute, it's possible that you have carpal tunnel syndrome. Another test is the Tinel test. This is where your GP taps or presses on your median nerve in your wrist to see if you get any tingling in your fingers.
Your GP may refer you for a nerve conduction test if they can’t be sure of the diagnosis or before you have surgery. This test can show if there is any damage to your median nerve. A trained technician attaches wires to your fingers and wrist, and applies small electric pulses to measure how quickly messages pass through your median nerve.
Treatment for carpal tunnel syndrome helps to relieve your symptoms by reducing the pressure on your median nerve. 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.
Resting your hands and wrists regularly may relieve mild symptoms of carpal tunnel syndrome. When your symptoms flare up, try applying a cold compress, such as an ice pack or ice wrapped in a towel. Don’t apply ice directly to your skin as it can damage it.
If repetitive hand movements are causing your condition, it's important to try to limit any activities that make your symptoms worse. It may help if you change the way you carry out these actions or reduce how often you do them. It may also help to increase the amount of rest you take between periods of activity. Some people find that changing their mouse or keyboard shape can help, but there is little evidence to suggest this is effective.
You may be offered steroid injections directly into your carpal tunnel. Your pain may get a little worse for a couple of days after the injection, but your symptoms should improve after that. However, you may find that your symptoms return after a few months, especially if they were serious to begin with. There’s no evidence that another injection will relieve your symptoms any further.
An injection is usually offered rather than steroid tablets. This is because it’s more effective and there are side-effect with the tablets if you take them for a long time. They aren’t usually recommended.
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may help to relieve pain in the short term. However, they can cause side-effects and there is little evidence that they have much effect on carpal tunnel syndrome unless it's caused by underlying inflammation.
Diuretic medicines (water tablets) don't appear to have any effect on the symptoms of carpal tunnel syndrome and aren’t recommended.
Wrist splints can help to keep your wrist straight and reduce pressure on the compressed nerve, and may relieve the symptoms of carpal tunnel syndrome. You’re likely to be advised to wear wrist splints at night for several weeks or months. Any improvement in your symptoms should happen within eight to 12 weeks. You can wear splints during the day as well, but you may find that they get in the way as you go about your daily routine.
Research has looked into whether ultrasound treatment can help reduce symptoms of carpal tunnel syndrome. At the moment, there’s not very much good evidence that suggests it may be effective. Further research is needed to find out how effective and safe this treatment is.
If your symptoms are severe or other treatments haven’t worked for you, your GP may suggest that you have carpal tunnel release surgery. This operation involves cutting your carpal ligament to make more space for the nerves and tendons in your carpal tunnel. Evidence suggests that the procedure is more effective for treating carpal tunnel syndrome than splinting. But more research is needed to see if it’s a better treatment than steroid injection.
There’s no scientific evidence that any general hand or wrist exercises can relieve the symptoms of carpal tunnel syndrome. More research is needed to see whether special hand exercises – called nerve and tendon gliding exercises - can help.
Some individual studies suggest that acupuncture helps to relieve symptoms of carpal tunnel syndrome but the evidence is limited. Furthermore, a recent review of studies on acupuncture for this condition didn’t show convincing benefits. More research is needed before we know if acupuncture is effective as a treatment for carpal tunnel syndrome.
There’s no evidence to suggest that chiropractic, vitamin B6 (pyroxidine) tablets or magnets can help. There is a small amount of evidence that yoga may help to reduce pain in some people with carpal tunnel syndrome, but more research is needed.
Always seek advice from your GP or pharmacist before trying any complementary therapies or medicines. If you choose to try a complementary therapy, check that your therapist is connected to a recognised organisation.
Reviewed by Natalie Heaton, Bupa Health Information Team, June 2014.
For answers to frequently asked questions on this topic, see FAQs.
For sources and links to further information, see Resources.
This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.