Signs of carpal tunnel syndrome

The carpal tunnel is a narrow passageway on the inner side of the wrist that a nerve and several tendons pass through. Carpal tunnel syndrome occurs when a nerve near the wrist is compressed by the surrounding tissue.

Which symptoms may be signs of carpal tunnel syndrome?

The following symptoms may occur:

• Sensations like numbness and tingling (pins and needles) in the affected hand: Numbness, and not pain, is the main symptom of carpal tunnel syndrome. A first and very typical sign is one hand falling asleep at night.
• Pain that can radiate out into the arm.
• Abnormal sensations and pain affecting the palm and all fingers except for the smallest (pinky).
• Difficulties moving the hand and opening and closing it. It becomes more and more difficult to grasp something with the hand.
• Limited use of the hand, up to and including muscle wasting, if the condition worsens.

Symptoms can be mild and last for years. They may also go away and then reoccur. In about 1 out of 5 people affected by carpal tunnel syndrome, symptoms improve without treatment within one year, but they can be so bothersome that treatment is desired.

What are possible causes?

Often, no external cause of carpal tunnel syndromecan be determined. A very thin wrist can sometimes be partially to blame for the condition. Other than that, there are different factors that may be responsible for someone getting carpal tunnel syndrome: for example too much strain or repeated strain on the wrist as well as rheumatoid, hormonal or metabolic disorders. But other things as well, for example a break in one of the bones of the forearm near the wrist (radius fracture) or a joint injury (dislocated wrist) may be the cause. Carpal tunnel syndromeoccurs mostly in women of middle and older age. Men are affected considerably less often. It often occurs on both hands at the same time.

How is carpal tunnel syndrome diagnosed?

Some of the symptoms mentioned above may also occur if the hands are overstrained or if strain is exerted incorrectly, for example in different types of sports, like tennis. Your hand may also fall asleep at night if you are lying in an uncomfortable position. Before you start to worry too much it is important – if needed, together with your doctor – to rule out any of these causes.

In addition to a physical examination, doctors use so-called electroneurography and sometimes electromyography as well, to make a diagnosis. Electroneurography measures how well the nerves carry electrical impulses. Electromyography registers how well the muscles respond to electrical stimuli. These tests can indicate problems with nerve functions. Yet they cannot produce a diagnosis on their own because they are not exact enough. They always have to be considered together with the symptoms, the physical examination, personal circumstances and medical history. It is also important for doctors to rule out any other causes of this condition. For example, changes in the cervical vertebrae may irritate the nerve roots. Other disorders of the nervous system (for example polyneuropathies) can also cause similar symptoms.

There are different treatment options for people with carpal tunnel syndrome. You can find out more about one specific treatment option here.

You can read more about carpal tunnel syndrome here.

Author: German Institute for Quality and Efficiency in Health Care (IQWiG)

© IQWiG (Institute for Quality and Efficiency in Health Care) Last update of this website: 05/22/2012