An EEG (Electroencephalogram) records the electrical activity of the brain using small electrodes placed on the scalp. It is painless and the main test for epilepsy and seizure disorders.
Why it is done
- Seizures / fits and epilepsy
- Fainting or unexplained blackouts
- Confusion or altered consciousness
- Follow-up of epilepsy treatment
Preparation
- Wash your hair the night before; do not use oil, gel or conditioner.
- Take your usual medicines unless your doctor advises otherwise.
- For a sleep-deprived EEG, sleep only a few hours the night before as instructed.
- Eat normally — low blood sugar can affect the recording.
Frequently asked questions about EEG
Is EEG safe for children?
Yes. EEG only records brain activity; nothing is passed into the body. It is commonly done in children.
How long does an EEG take?
A routine EEG takes about 30–45 minutes including electrode placement.
Page reviewed by the radiology team at Kansal Diagnostic Centre · Updated October 2026