Electroencephalogram (EEG)

Key facts An electroencephalogram (EEG) is a test that records your brain activity. It can be used to diagnose different conditions such as epilepsy or sleep disorders. To prepare for an EEG, your hair should be clean and dry. During an EEG, discs called electrodes will be placed on your scalp to measure your brain waves. An EEG is non-invasive and does not hurt. What is an EEG test? Your brain cells produce electric signals to communicate with each other and the rest of your body. An electroencephalogram, or EEG, is a test that measures the electrical activity of your