Carpal Tunnel Syndrome: Causes, Symptoms, Treatment and Prevention

Carpal tunnel syndrome is a condition characterised by numbness, tingling, pain or weakness in the hand. This happens when the main median nerve in the forearm becomes compressed as it passes through the carpal tunnel – a passageway of tissues and bones at the wrist and base of the hand. Sensation in the thumb, index and middle fingers and half of the ring finger is affected.

The symptoms are often felt at night and after waking up in the morning. In the early stages, the hand may occasionally feel numb and tingle mildly when gripping a bus handrail for too long, holding a book, using the telephone or cutlery, typing or doing household chores.

Later, the numbness and tingling become more persistent, which can keep the person awake at night. As the condition worsens, permanent damage to the nerve may occur. At this stage, much of the hand may lose its feeling and the muscles at the base of the thumb become weak.

Several factors can increase your risk of developing carpal tunnel syndrome:

Repetitive hand and wrist movements: Hand-intensive work, such as prolonged use of vibrating tools or power tools, has frequently been associated with carpal tunnel syndrome. Repetitive bending of the wrist and hand may cause tendons and sheaths in the carpal tunnel to swell. This occurs commonly with people who use their hands for prolonged periods, like in computer work or assembly line workers. However, the debate on the relationship between repetitive motion and the condition is still ongoing.

Wrist positioning: Carrying out activities or sleeping with the wrist bent puts undue strain or pressure on the median nerve.

Pregnancy: Fluid retention during pregnancy causes swelling of tissues in the carpal tunnel, which may include the median nerve itself.

Previous wrist injuries: Previous dislocation or fracture of the wrist may cause the bone to protrude into the carpal tunnel, putting pressure on the median nerve.

Underlying health conditions: Often, the cause is unknown, although people who suffer from certain conditions appear to be more prone due to increased pressure within the carpal tunnel. Diagnosis of carpal tunnel syndrome may reveal a more serious underlying health condition during examination such as diabetes or rheumatoid arthritis.

Your doctor will carry out a physical examination and may conduct tests such as a nerve conduction study (NCS) and an electromyography (EMG) to diagnose carpal tunnel syndrome.

Carpal Tunnel Syndrome Treatment

There are several treatment options which can be used alone or in combination, depending on the severity of the condition.

Non-Surgical Treatment

When the symptoms are still mild, treatment may include:

Wrist splint or brace: Wearing a splint or wrist brace at night helps minimise wrist movement and relieves pain.

Medication: Anti-inflammatory drugs and vitamin B6 may help manage symptoms.

Steroid injections: Corticosteroid injection into the carpal tunnel can reduce swelling of the tissues. However, such treatment only provides temporary relief and does not cure the underlying problem.

Heat therapy: Applying a warm towel or hot pack can provide relief.

Median nerve gliding/tensioning exercises: These exercises can help improve nerve mobility.

Activity modification: Adjusting how you perform daily tasks can reduce strain on the wrist.

Surgical Treatment

Surgery to divide the transverse carpal ligament – the fibres across the palm below the fingers – that presses down on the nerve is recommended when the symptoms persist, especially if they are affecting the patient's quality of life. The surgery releases the carpal ligament, taking pressure off the median nerve.

Minor surgery is often done under local anaesthesia, with the procedure completed within half an hour. The choice of surgical procedure lies between open carpal tunnel release and endoscopic carpal tunnel release (keyhole or minimally invasive surgery), with its advantages of a small incision and shorter recovery.

When the nerve has sustained irreversible damage, carpal tunnel release surgery is still recommended. Although the pre-existing damage will not be reversed, surgery will help prevent a worsening of the condition that could lead to complete paralysis of the thumb muscles.

Maintain proper wrist positioning: Try to maintain a neutral (straight) wrist position. Avoid prolonged positioning of the wrist at extreme range, e.g. holding up newspapers whilst resting forearm on table surface, typing with wrists extended.

Avoid tight gripping: Avoid using a tight grip whilst working with a pen, computer mouse or other hand-held devices. Avoid forceful gripping activities.

Take regular breaks: Give your hands and wrists frequent breaks. Take frequent rest breaks in activities that require repetitive use of the hand and wrist.

Avoid repetitive movements: Avoid repetitive movements or holding an object in the same way for prolonged periods of time.

Keep hands warm: Keep your hands warm if your work environment is cold.

Do stretching exercises: Do regular hand and wrist stretching exercises.