Carpal tunnel syndrome | Mate kāwititanga o te ringa

Key points

1. Carpal tunnel syndrome usually starts with a tingling or numbness in your hands and fingers, and becomes increasingly painful.
2. It is 5 times more common in women than in men and occurs most often in people aged between 30 and 60. 
3. It also occurs more often during pregnancy and in people with certain long-term conditions. 
4. It may be brought on by repetitive activities at work, sport or other recreational activities.
5. Treatment aims to reduce pain, tingling and numbness, and restore wrist and hand function.

What causes carpal tunnel syndrome?

The main symptoms of carpal tunnel syndrome are thought to be caused by irritation to the median nerve in the carpal tunnel.

The carpal tunnel is a narrow space inside your wrist that is surrounded by bone and ligament. This tunnel protects the finger tendons, nerves and blood vessels where they pass from your forearm into your hand.

• With carpal tunnel syndrome, the carpal tunnel swells and compresses the median nerve.
• This could be caused by thickening of the tendon sheaths, which reduces the amount of space inside the carpal tunnel.
• As a result, the median nerve may be compressed, and you then feel pain and tingling, particularly on the thumb side of your palm, your thumb and your fingers.

What are the symptoms of carpal tunnel syndrome?

Carpal tunnel syndrome usually starts with a tingling (pins and needles) or numbness, particularly in your thumb, index finger (forefinger or pointing finger) and middle finger. There may also be general discomfort or numbness in your wrist or arm, and slight weakness of your hand grip. Some people get swelling in their fingers. Symptoms may wake you up at night, but they may also occur during the day. For instance, you may notice symptoms while you are driving or holding a newspaper.

How is carpal tunnel syndrome diagnosed?

Carpal tunnel syndrome is usually diagnosed by your doctor or physiotherapist. They will perform a physical examination and ask questions to learn more about your symptoms. For example, they will ask about the numbness or tingling you feel, where and when you feel it, and for how long.

Further testing is only required if they want to rule out other conditions that have similar symptoms. Other tests that your doctor may recommend can include:

• Blood tests – if your doctor suspects 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, you and your health professional will make a treatment plan.

How is carpal tunnel syndrome treated?

Treatment for carpal tunnel syndrome depends on how bad your symptoms are and how long you have had them. Treatment will also depend on whether you have other conditions that need further treatment such as arthritis, diabetes or another injury. The aim of treatment is to reduce the pressure in the carpal tunnel space. Some people find that symptoms improve within a few weeks. 

Self-care

Self-care is the first option, particularly if your symptoms are mild or have started during pregnancy. You may be able to ease your discomfort by:

• taking frequent breaks from repeated activities to rest your hands
• changing your wrist position
• avoiding activities or movements that make symptoms worse
• avoiding prolonged, repetitive or strong gripping of objects
• avoiding extreme bending of your wrist
• avoiding 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
• applying cold packs to reduce any swelling
• using a removable support (splint) to keep your wrist straight. You can use it during the night or the day, depending on when your symptoms are worst. Splints can often be bought over the counter from a pharmacy.

Note: Squeezing a ball is not helpful for this condition.

Other treatment

If self-care does not relieve your symptoms within a few weeks, or you notice a reduction in the size of the muscles at the base of your thumb, talk to your doctor or physiotherapist. If you leave the condition untreated while your symptoms get worse, permanent nerve and muscle damage can occur. There are a range of treatments available.

• Physiotherapy or hand therapy may be helpful. It can improve the mobility of your wrist bones and the flexibility of soft tissues in your arm. You may also be given strengthening exercises.
• Physiotherapists can also provide strategies and solutions for activities at work, such as when using a keyboard.
• Pain medication such as paracetamol may provide relief.
• Your doctor may offer cortisone injections, which can also provide short-term relief. 

It is also important to manage any underlying causes, such as diabetes. Losing weight, if you are overweight or obese, is likely to reduce the symptoms.

Treatment for severe symptoms

If symptoms persist for more than 6 months and are interfering with your daily life and work activities, despite self-care and treatment, you may need surgery. Surgery relieves pressure on the trapped nerve and aims to prevent any permanent nerve damage. Your doctor will be able to discuss the most suitable method of surgery with you.

Learn more

The following links have more information about carpal tunnel syndrome. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Carpal tunnel syndrome Mayo Clinic, US 
Carpal tunnel syndrome NHS Choices, UK
Carpal tunnel syndrome OrthoInfo, US
Carpal tunnel syndrome – patient information Capital & Coast DHB, NZ, 2020

Reviewed by

	Gisela Sole is associate professor at the School of Physiotherapy, University of Otago, Dunedin. She is a physiotherapist, currently focusing on education and research that explores optimal management for individuals with musculoskeletal pain and injury, with special interest in persistent shoulder pain and knee injuries.
	Miranda Bűhler is a physiotherapist and hand therapist with 20 years’ clinical experience. She works at Southern District Health Board. Her clinical and research interests cover a wide range of post-traumatic and long-term conditions involving the hand and upper limb. She is currently completing her PhD at the University of Otago.