Carpal tunnel syndrome | Mate kāwititanga o te ringa

The carpal tunnel is a narrow space in your wrist that’s surrounded by bone and ligament. It guides the tendons that bend your fingers where they pass from your forearm into your hand. Squeezed in along side the tendons is the nerve that gives the feeling to your thumb, index, middle and half of your ring finger.

Carpal tunnel syndrome is caused by pressure on the median nerve, one of the main nerves of your hand, as it goes through the carpal tunnel. The 2 main things that influence the pressure in the tunnel are:

• the position of your wrist, and
• the amount of load on your tendons.

Sometimes, narrowing of the tunnel, or inflammation or thickening of the tendons, can also be part of the problem. When the pressure in the tunnel increases, it interferes with how the median nerve sends its messages, causing numbness, tingling, pain and sometimes weakness in your hand.

Image credit: 123RF

Risk factors for carpal tunnel

• Being female.
• Pregnancy – up to about 50% of pregnant women develop hand and finger pain, possibly due to fluid retention in the carpal tunnel.
• Other health conditions, such as:
  • diabetes, which can make nerves more sensitive
  • rheumatoid arthritis, which can cause inflammation of the tendons in your wrist, and
  • hypothyroidism.
• Doing repetitive work with your hand, especially things where you often have to bend or extend your wrist or grip hard.
• Being very overweight.
• Having a family history of carpal tunnel syndrome – this is because your genes influence things such as the shape of your carpal tunnel.
• Injury to your wrist.

Carpal tunnel syndrome usually starts with tingling (pins and needles) or numbness, particularly in your thumb, index finger (forefinger or pointing finger) and middle finger. You may also have pain or numbness in your wrist or arm, and slight weakness of your hand grip. Some people get swelling in their fingers. You may have symptoms in both hands. 

It’s common for symptoms to be worse at night and they may wake you up, but symptoms may also occur during the day. For instance, you may notice symptoms while you’re driving or using your phone.

Carpal tunnel syndrome is usually diagnosed by your healthcare provider or physiotherapist. They’ll examine your hand and wrist and ask questions to learn more about your symptoms. For example, they’ll ask about the numbness or tingling you feel, where and when you feel it, and for how long.

Further testing is only needed if they want to rule out other conditions that have similar symptoms. Other tests that may be recommended include:

• blood tests – if it's thought you may have an underlying condition such as diabetes, rheumatoid arthritis or underactive thyroid.
• nerve conduction study – to find out if there are changes in the function of the nerves in the wrist and hand.
• X-ray – to exclude other causes of wrist pain, such as arthritis or a fracture.
• ultrasound scan – to examine the structure of your wrist.

Once your problem is diagnosed as carpal tunnel syndrome, your healthcare provider will make a treatment plan with you.

Treatment for carpal tunnel syndrome depends on how bad your symptoms are and how long you’ve had them. Treatment will also depend on whether you have other conditions that need further treatment such as arthritis, diabetes or an injury.

The aim of treatment is to reduce the pressure on the median nerve in your carpal tunnel. Some people find that their symptoms improve within a few weeks. If you’re pregnant, the symptoms of carpal tunnel syndrome often go away after your baby has been born.

ACC(external link) may cover treatment of your carpal tunnel syndrome if it’s caused by work-related activities.

Self-care

Self-care is the first option when treating carpal tunnel syndrome, particularly if your symptoms are mild or have started during pregnancy. See the self-care section below for things you can do to help ease your symptoms.

Other treatment

If self-care doesn’t relieve your symptoms within a few weeks, or you notice that the muscles at the base of your thumb look smaller than usual (this is known as muscle wasting), talk to your healthcare provider or physiotherapist. Permanent nerve and muscle damage can occur if your carpal tunnel syndrome gets worse and isn’t treated. 

• Physiotherapy or hand therapy may be helpful. It can improve the movement of your wrist bones and the flexibility of soft tissues in your arm. You may also be given strengthening exercises.
• Physiotherapists can also provide advice on changing the way you do things at work, such as how you use your keyboard. 
• Pain medication such as paracetamol may provide relief.
• You may be offered cortisone injections, which can also provide short-term relief (up to 3 months). 

Treatment for prolonged or severe symptoms

You may need surgery if your symptoms are severe or don’t get better after 6 months – especially if they’re interfering with your daily life and work activities despite self-care and treatment. Severe symptoms include loss of sensation in your hand or fingers and muscle wasting at the base of your thumb.

Surgery relieves pressure on the trapped nerve in your wrist and aims to prevent any permanent nerve damage. Your healthcare provider can refer you to a specialist (an orthopaedic surgeon) who can discuss the most suitable type of surgery with you.

Try these things to help ease your discomfort from carpal tunnel syndrome.

• Take frequent breaks from repeated activities to rest your hands.
• Change your wrist position.
• Avoid activities or movements that make your symptoms worse, such as using vibrating tools at work, or playing an instrument.
• Avoid prolonged, repetitive or strong gripping of objects.
• Avoid extreme bending of your wrist.
• Avoid gripping equipment or tools that are narrow and slippery as they require more force to hold onto – it may help to get wider and less slippery equipment or tools.
• Apply cold packs to reduce any swelling.
• Pain medicines, such as paracetamol or ibuprofen, may provide short term relief.
• Use a removable support (splint) to keep your wrist straight and relieve pressure on your nerve. You can use it during the night or day, depending on when your symptoms are worst. Splints can often be bought over the counter from a pharmacy.
• Losing weight, if you’re overweight or obese, is likely to reduce your symptoms.

Note: Squeezing a ball is not helpful for carpal tunnel syndrome.

Apps reviewed by Healthify

You may find it useful to look at some nutrition, exercise and weight management apps.

Clinical resources

Management of carpal tunnel syndrome – evidence-based clinical practice guideline(external link) American Academy of Orthopaedic Surgeons, US, 2024
Carpal tunnel syndrome(external link) Ortho Bullets, US, 2024
Surgical versus non-surgical treatment for carpal tunnel syndrome(external link) Cochrane Database of Systematic Reviews, UK, 2024
CTS-6 evaluation tool(external link) East Bay Hand Medical Center, US

Continuing professional development

Video: Cortisone injection for carpal tunnel syndrome

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(Counties Manukau Health Orthopaedics, NZ)