Electromyogram (EMG)
What is an electromyogram?
An electromyogram, or EMG, is a test that checks the response of muscles to messages sent by the nerves. The test measures the electrical activity of muscles in response to stimulation.
When is it used?
An electromyogram can help diagnose problems such as:
- nerve damage or injury caused by a compressed disk in the neck or back
- nerve compression in the hand from carpal tunnel syndrome
- muscle or movement problems, such as involuntary muscle twitching
- muscle weakness from nerve disorders or diseases such as muscular dystrophy
- nerve problems caused by conditions such as diabetes, pernicious anemia, and heavy metal poisoning.
How do I prepare for an electromyogram?
Tell your healthcare provider before the test if:
- You have any bleeding problems.
- You have a pacemaker.
- You have allergies.
- You are taking any medicines.
On the day of the test, take a shower to remove oil from the skin. Don’t put any lotions or creams on your skin before the test.
How is the test done?
First you may be given a sedative to relax you. Your healthcare provider will insert several small needle electrodes through your skin into the muscles. Usually they are inserted in the area where you are having symptoms. The electrodes record the electrical activity of the muscles. Muscles may be tested when they are resting, when contracting gently, and when contracting forcefully. The test takes about 30 to 60 minutes to perform, depending on the number of muscles being tested.
What happens after the test?
The muscles may feel tender or bruised for a few days after the test.
How will I get the test result?
Ask your healthcare provider when and how you will get the result of your test.
Developed by RelayHealth.
Adult Advisor 2012.1 published by RelayHealth.
Last modified: 2011-06-22
Last reviewed: 2011-04-03
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
© 2012 RelayHealth and/or its affiliates. All rights reserved.
