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. They will look for signs of weakness in the muscles surrounding your thumb, as this can indicate CTS.
Physical tests
A physical test that may be used by your GP to help diagnose CTS involves tapping your wrist lightly to see whether it produces a tingling feeling or numbness in your affected hand.
Another test involves flexing your wrist for a minute to see if you feel pain, numbness or tingling in your hand.
If you do have these sensations, this may mean that your median nerve is being compressed (squashed) and is causing your symptoms.
Further testing
Further testing is usually only required if your GP is uncertain about the diagnosis and wants to rule out other conditions that have similar symptoms. Further tests that may be used are described below.
Blood tests
If your GP thinks that your CTS may be linked to an underlying condition, they may decide to carry out a blood test. There are a number of health conditions that increase the risk of developing CTS and your GP will want to find out if you have any of them, such as:
See Carpal tunnel syndrome – Causes for more information about these conditions.
Nerve conduction study
A nerve conduction study is a test that measures how fast signals are transmitted through your nerves. During the test, electrodes (small metallic discs) are placed on your hand and wrist. The electrodes produce a small electrical current that stimulates the nerves in the wrist, fingers and forearm.
The results from the test will be used to assess any possible damage to your nerves.
Electromyography
Electromyography involves inserting fine needles into your muscles. The needles detect any natural electrical activity that is given off by your muscles. You may be able to see the activity on a monitor (an oscilloscope) or hear it through a speaker.
Electromyography provides useful information about how well your muscles are able to respond when a nerve is stimulated and can indicate whether there is any nerve damage.
Electromyography and nerve conduction studies can help to establish how severely the median nerve is being compressed and the effect it is having on your symptoms.
X-ray
If your GP suspects that you may have an injury to your hand, such as a sprain or fracture, you will need to have an X ray. An X-ray is a procedure that uses radiation to produce images of the inside of your body.
Other procedures
To thoroughly examine the structure of the median nerve in your hand, your GP may also suggest that you have:
- an ultrasound scan – this uses high-frequency sound waves to produce an image of the inside of your body
- a magnetic resonance imaging (MRI) scan – this is a type of scan that uses strong magnetic fields and radio waves to produce a detailed image of the inside of your body
