Carpal tunnel syndrome (CTS) is a relatively common condition that causes pain, numbness and a burning or tingling sensation in the hand and fingers. Symptoms of CTS can range from mild to severe.
The carpal tunnel
The carpal tunnel is a small tunnel that runs from the bottom of the wrist to the lower palm.
Several tendons that help to move the fingers pass through the carpal tunnel. So does the median nerve, which controls sensation and movement of your hand.
On the inner side of the wrist the carpal tunnel is enclosed within tissue called the transverse carpal ligament.
In cases of CTS, the space inside the tunnel is made smaller by the increased tissue pressure and a build-up of fluid in the tissue (oedema). This places pressure on the median nerve. The pressure is increased further when the wrist and fingers are bent (flexion). Compression of the median nerve causes the symptoms of pain and numbness.
See Carpal tunnel – Symptoms for more information.
How common is CTS?
CTS is more common in women than men. In the UK each year, around 60 to 120 women out of every 100,000 are affected by the condition compared with 35 to 60 men out of every 100,000.
The two most common age-ranges for developing CTS are between 50 to 54 and 75 to 84.
CTS is also a common condition during pregnancy, affecting up to 50% of pregnant women. It is thought that this may be due to the fluid retention that often occurs during pregnancy, which places additional pressure on the carpal tunnel and causes symptoms.
Outlook
The outlook for CTS depends on the severity of the symptoms. People with mild to moderate symptoms usually respond well to non-surgical treatments, such as wrist splints and corticosteroid injections. In more severe cases of CTS, surgery is usually required to reduce the pressure on the median nerve.
See Carpal tunnel syndrome – Treatment for more information about the treatment options for CTS.
Cases of CTS during pregnancy are usually less severe than those where the cause is unknown cause (idiopathic). It is less likely that CTS during pregnancy will require surgical treatment.
CTS in pregnant women often gets better with three months of the baby being born. However, in some women, symptoms can continue for over a year.
If CTS is recognised early it can usually be treated. However, if it is left untreated it can lead to chronic weakness of the hand, numbness and nerve damage.
