Carpal tunnel syndrome

The carpal tunnel is a narrow passage in your wrist that your median nerve and the tendons to your thumb and fingers pass though. Carpal tunnel syndrome is caused by pressure on the median nerve.

Anything that causes swelling in the carpal tunnel can cause carpal tunnel syndrome. We do not always know why this swelling happens, but some conditions are linked to carpal tunnel syndrome. These include: 

• pregnancy (due to extra fluid retained in your body and changes to your posture)
• being overweight
• fluid retention
• diabetes 
• hypothyroidism
• rheumatoid arthritis and connective tissue diseases
• wrist wounds or broken bones.

Carpal tunnel syndrome can also happen after hard or repetitive movements of your wrist or hand. ACC may cover carpal tunnel syndrome if it has been caused by work tasks. 

Symptoms of carpal tunnel include:

• tingling, burning or numbness in the thumb and fingers
• pain in your wrist or fingers that sometimes moves up to your elbow
• weakness or difficulty with picking up or gripping things.

One or both hands may be affected. Your symptoms may be particularly bad at night or first thing in the morning, or when doing the same task for a long time, like long-distance driving.

Your healthcare provider will ask you about your symptoms and examine your wrist and hand.  

They may also suggest you have a nerve conduction study if they are not sure you have carpal tunnel syndrome. This study tests to see how well and how quickly your nerves conduct electrical signals. 

• Avoid or reduce repetitive hand and wrist activities that may make your symptoms worse.
• Try to rest with your hand and arm raised when possible.
• Try to keep your wrist in a relaxed position through the day.
• Keep your back supported and upright when sitting, and your shoulders back.
• Adjust the height of your seat or keyboard when at a computer so your wrist is in a relaxed position.
• Use a thick enough pillow to keep your neck supported when sleeping.
• Try putting your hand in a bowl of warm water and then moving it to a bowl of cold water (with ice cubes). Hold your hand in each bowl for 30 seconds, alternating between the bowls for 10 minutes in total — this can help improve symptoms.
• Try gentle massage — stroking upwards from your hand towards your armpit. This can help reduce any swelling in your carpal tunnel.
• Stretch your arms out to the sides of your body, pull your shoulder blades back together and straighten your arms, wrists and fingers backwards.

Find a registered hand therapist — Hand Therapy New Zealandexternal link

There are several treatments for carpal tunnel syndrome, depending on how severe your symptoms are.  

• Talk to your healthcare provider about treating any conditions that could be causing or making it worse.  
• Carpal tunnel wrist splints can help stop or reduce pain or numbness especially at night, by preventing the median nerve from being squeezed.
• Steroid injections can ease the pain and symptoms of carpal tunnel syndrome.

Your healthcare provider may refer you for surgery if your symptoms have not improved after other treatments, or your symptoms are very bad. 

Carpal tunnel release (or decompression) surgery aims to make more space in the carpel tunnel to take the pressure off your median nerve. It is generally very effective. If there are signs your nerve is damaged, then surgery aims to stop it getting worse. It may not be able to completely reverse any existing damage. Some symptoms can get better immediately after the operation, but numbness can take longer to improve.