Carpal tunnel syndrome is a common condition that occurs when there is too much pressure on a nerve in the wrist. There is usually aching, numbness or tingling in the thumb, some of the fingers and sometimes part of the hand.

About 3 in 100 people develop carpal tunnel syndrome at some point in their life. Over half of these are women. While it can develop at any age, the chance of it occurring increases with age. It is most common in people in their 40s and 50s.

Sometimes carpal tunnel syndrome can be triggered by your job. It can sometimes be prevented by stopping or reducing the activity that stresses your fingers, hand, or wrist, or by changing the way in which activities are done.

Because there isn't much room in the carpal tunnel, any swelling around it can compress the median nerve, causing the symptoms of carpal tunnel syndrome.

Symptoms include aching, tingling, "pins and needles", a swollen feeling, burning, numbness or pain in the hand and fingers. Only fingers served by the median nerve - the thumb, the index and middle fingers, and part of the ring finger - are affected.  Sometimes, the symptoms can spread up your arm.

Carpal tunnel syndrome tends to be worse at night or first thing in the morning and is often made worse by strenuous wrist movements. You may find that you get temporary relief by hanging your arm out of the bed at night or by shaking your hand vigorously with a flicking action.

It can affect one or both hands to varying degrees. Symptoms may be mild or only occur from time to time, but if the condition worsens they may become constant. Your hand muscles may become weakened, making it difficult to grip objects or perform other manual tasks. In severe, long-lasting cases the thumb muscles may start to waste away or the median nerve may be permanently damaged.

The condition is more likely to develop if you have sprained or previously broken your wrist, which can lead to swelling. The carpal tunnel may also be compressed through rheumatoid arthritis..

Another cause is pressure within the tunnel due to fluid retention. This can happen if you have kidney failure, have an underactive thyroid, or are pregnant. Carpal tunnel syndrome is also more common in people who are very overweight, in women who are taking the contraceptive pill, and during the menopause.

It can be caused by changes to the median nerve itself, too, which may happen if you have diabetes or drink excessive amounts of alcohol.

To diagnose carpal tunnel syndrome, our doctor may carry out a nerve conduction test. To do this, wires are attached to your fingers and wrist, and small electric shocks applied. The doctor can then assess nerve conduction and find out if there is any damage to the median nerve.

If your symptoms continue to get worse and the cause of the carpal tunnel syndrome can't be removed, your doctor may suggest carpal tunnel release surgery.

This operation involves cutting the carpal ligament to make more space for the nerves and tendons in the carpal tunnel. It can usually be done as day-case surgery. It can be carried out in two ways.

• Keyhole surgery - a thin flexible telescope (endoscope) is inserted into a small cut in the wrist allowing the surgeon to see inside the wrist and cut the carpal ligament.
• Open release surgery - a traditional open operation, where a longer cut of around 6cm is made in the wrist allowing the carpal ligament to be cut.

Endoscopic surgery leaves a smaller scar, and some studies suggest that it allows people to get back to their usual activities more quickly. However, there may be a slightly higher risk of nerve damage. Our doctor will advise you on the most suitable type of surgery for you.

Most people will improve after surgery, but it can take several months to recover.