What is an electroencephalogram (EEG)?

An electroencephalogram, or EEG, is a test that measures electrical activity in the brain. This activity shows up as wavy lines on an EEG recording. EEGs are used to diagnosis epilepsy and sleep disorders, and to monitor anesthesia. They may also be used to help diagnose other conditions, such as brain tumors and head injuries. To prepare for an EEG, you will likely be asked to remove any metal objects from your hair, such as hair clips or barrettes. You may also be asked to wash your hair to remove any oils, which can interfere with the EEG.

During the test, small, metal discs (electrodes) will be attached to your scalp. The electrodes are connected to an EEG machine, which records the electrical activity. You will be asked to sit still during the test, as movement can interfere with the EEG.

The test itself is painless. However, some people may feel a slight tingling sensation when the electrodes are first attached. EEGs typically last for 30-60 minutes. Once the test is complete, the electrodes will be removed and you will be able to return to your normal activities. There is no preparation required for an EEG. However, you may want to schedule the test for a time when you are well rested, as fatigue can impact the results.