Carpal tunnel syndrome is a condition that causes pain or weakness in the forearm and hand. It's caused by pressure on a nerve in the wrist.
About carpal tunnel syndrome
Your carpal tunnel is a channel in the palm side of your wrist. It’s formed by the semi-circle of wrist bones with a tough ligament known as the transverse carpal ligament forming a roof over these bones. The carpal tunnel surrounds the tendons you use to bend your fingers and wrist. It also surrounds your median nerve, which is one of three nerves that connect your wrist to your hand and controls some of the muscles that move your thumb.
You can get carpal tunnel syndrome if there’s too much pressure on your median nerve.
About three in 100 men and five in 100 women develop carpal tunnel syndrome at some point in their life.
Symptoms of carpal tunnel syndrome
If you have carpal tunnel syndrome, your hand and fingers may:
- feel numb
You're most likely to get these symptoms in your thumb, index and middle fingers and the side of your ring finger nearest your thumb. You may also get aching or pain in your forearm, shoulder and neck. Your symptoms may be mild or may last for only short periods of time.
Carpal tunnel syndrome tends to be worse at night or first thing in the morning. Your symptoms may get better after you’ve used your hand for a while, but may then come back later in the day.
If you have these symptoms, contact your GP for advice.
If your symptoms occur constantly, your hand muscles can become weak. This may make it more difficult for you to grip objects or perform other manual tasks. 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. Occasionally, you may experience changes to the colour and feel of the skin of your hand.
Causes of carpal tunnel syndrome
Because there isn't much room in your carpal tunnel, any swelling around it can press on your median nerve, causing the symptoms of carpal tunnel syndrome.
You're more likely to develop the condition if you're overweight or have a job where you use your hands a lot. You may also get carpal tunnel syndrome if you:
- have a job that involves repeated forceful movements of your wrist, such as using a screwdriver
- have rheumatoid arthritis in your wrist joint
- are pregnant
- have thyroid problems
- have acromegaly – a condition caused by too much growth hormone in the body
- have diabetes
- have cysts in your carpal tunnel.
Carpal tunnel syndrome is more likely to affect women than men, and it tends to develop in pregnant women and those aged between 40 to 60. People who repeatedly use their hands, people who tend to rapidly put on weight and people with arthritis are also at risk of developing the syndrome.
One in four people who have carpal tunnel syndrome has a relative who also has the condition.
Diagnosis of carpal tunnel syndrome
Your GP will ask you about your symptoms and examine you. They may also ask you about your medical history.
They may tap on your wrist and ask you to bend the palm of your hand to see if they can reproduce the symptoms of carpal tunnel syndrome. If this happens, it's likely that you have the condition.
If your GP isn't sure whether you have carpal tunnel syndrome, they may refer you to a neurologist (a doctor who specialises in conditions that affect the nervous system) for a nerve conduction test. This test can show if there’s any damage to your median nerve.
During the test, the neurologist will attach wires to your fingers and wrist and apply small electric shocks to measure how quickly messages pass through your median nerve.
Treatment of carpal tunnel syndrome
Treatment helps to relieve your symptoms by reducing the pressure on your median nerve and may stop your condition getting any worse.
Sometimes carpal tunnel syndrome improves after six months without any treatment, especially if you're pregnant or under 30.
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 make repetitive movements, reduce how often you do them and increase the amount of rest you take between periods of activity.
Resting your hands and wrists regularly may relieve mild symptoms of carpal tunnel syndrome. Shaking your hands when they’re numb or tingling may also help.
When your symptoms flare up, try applying a cold compress, such as an ice pack or ice wrapped in a towel. You shouldn't apply ice directly to your skin as this can damage your skin.
Making ergonomic corrections at your workplace, such as adjusting the position of your keyboard to maintain your wrist in a neutral position and using a wrist pad can help provide relief.
Wrist splints can help to keep your wrist straight and reduce pressure on the compressed nerve. Your doctor may recommend that you wear wrist splints either at night, or both day and night, although you may find they get in the way of daily activities.
Your GP may prescribe some medications to help manage your carpal tunnel syndrome. Sometimes, an injection containing corticosteroid and local anaesthetic may be used to help manage your symptoms.
Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may not have much effect on carpal tunnel syndrome unless it's related to an underlying inflammatory condition.
If you also have fluid retention in your wrist then your doctor may recommend diuretic medicines (fluid tablets) to help, but they are less likely to help resolve your carpal tunnel symptoms alone.
Some medicines can cause side effects if you take them for a long time. Always read the accompanying consumer medicines information leaflet and if you have any questions or concerns ask your pharmacist or GP for advice.
If your symptoms are severe, your GP may refer you to a specialist to check whether carpal tunnel release surgery may be suitable. This operation involves a surgeon cutting your carpal ligament to make more space for the nerves and tendons in your carpal tunnel. It's usually done as day-case surgery under a local anaesthetic.
Workers Health Centre
RSI and Overuse Injury Association of ACT
Better Health Channel. Carpel tunnel syndrome. [online] 2012 [Last updated July 2012, accessed May 2019] Available from: www.betterhealth.vic.gov.au
Merck Manuals Professional version. Carpal Tunnel Syndrome. [online] 2018 [Last updated October 2018, accessed May 2019] Available from: www.merckmanuals.com
Victorian Brain and Spine Centre. Carpal tunnel syndrome. [online, accessed May 2019] Available from: www.vbsc.org.au