Carpal tunnel syndrome (CTS) is a common condition that causes a tingling sensation, numbness and sometimes pain in the hand and fingers.

These sensations usually develop gradually and start off being worse during the night. They tend to affect the thumb, index finger and middle finger.

It is estimated that 3% of the population is affected by the syndrome, which is more common among women.

Pain is often reflected up to the arm. By night symptoms in the hand and fingers worsen with feelings of burning, itching and tingling that disrupt sleep. In very severe cases there is a risk of loss of sensation or partial paralysis of the hand (thumb). The condition is caused by compression of the median nerve in the wrist.

The carpal tunnel is a narrow passage in your wrist made up of small bones and a tough band of tissue that acts as a pulley for the tendons that bend the fingers.

In most cases, it isn't known why the median nerve becomes compressed.

However, some things do increase the risk of CTS.

This includes

• a family history of CTS
• pregnancy – up to about 50% of pregnant women develop CTS
• injuries to the wrist
• other health conditions, such as diabetes and rheumatoid arthritis
• strenuous, repetitive work with the hand

CTS is more common in women and becomes more likely as you get older.

The symptomatology begins with numbness in the first three fingers of the hand. It mainly occurs during the evening hours. Later there is pain which may be reflected in the entire upper extremity. In more severe cases weakness occurs during bending of the fingers and especially during abduction and opposition of the thumb.

The differential diagnosis is mainly made with conditions characterised by damage of the median nerve at a level other than that of the wrist. Such conditions are pronator syndrome, brachial plexus lesions and cervical diseases (compression injuries of spinal nerve roots).

Other diseases or conditions can also cause the appearance of the syndrome such as gout, rheumatoid arthritis, obesity, diabetes mellitus, pregnancy.