Diagnosing carpal tunnel syndrome 

Carpal tunnel syndrome (CTS) can usually be diagnosed by your GP, who will examine your hand and wrist and ask you about your symptoms.

Your GP will assess your ability to use your hand, wrist or arm and look for signs of weakness in the muscles surrounding your thumb.

Physical tests

Your doctor may tap your wrist lightly to see if you feel tingling or numbness in your fingers, although this test is not reliable.

Flexing your wrist or holding it elevated above the head for a minute are other commonly performed simple tests for CTS, and should induce the same pain, numbness or tingling in your hand if you have the condition.

Any of these sensations may be the result of your median nerve being compressed. These tests are often enough to diagnose CTS if you have typical symptoms.

Further testing

Further testing is usually only required if your GP is uncertain and wants to rule out other conditions that have similar symptoms. Further tests include:

Blood tests

A blood test can be used if the doctor suspects an underlying condition relating to CTS, such as:

Nerve conduction study

A nerve conduction study is a test that measures how fast signals are transmitted through your nerves. During the test, electrodes are placed on your hand and wrist and a small electrical current is used to stimulate the nerves in the finger, wrist and, sometimes, elbow.

The results from the test indicate how much damage there is to your nerves.  


Electromyography (EMG) provides useful information about how well your muscles are able to respond when a nerve is stimulated, indicating any nerve damage.

During the test, fine needles are inserted into your muscles. The needles detect any natural electrical activity given off by your muscles.

However, electromyography is rarely used for carpal tunnel syndrome in the UK because nerve conduction studies are usually able to confirm the diagnosis and measure the degree of damage to the nerve.

Imaging studies

An X-ray may be recommended, but usually only to aid in the diagnosis of fractures and other disorders such as rheumatoid arthritis. An X-ray is a procedure that produces images of the inside of your body.

To thoroughly examine the structure of the median nerve in your hand, your GP may also suggest you have an ultrasound scan, which uses high-frequency sound waves to produce an image of the inside of your body.

Page last reviewed: 18/09/2014

Next review due: 18/09/2016