How Doctors Diagnose Seizures and What Patients Should Know
Learn how epilepsy differs from seizures and the key tools doctors use to diagnose it.
By
Lana Pine
| Published on November 19, 2025
2 min read
In an interview with The Educated Patient, Dileep Nair, M.D., section head of adult epilepsy and director of intraoperative neurophysiologic monitoring at Cleveland Clinic, helps patients understand the difference between seizures and epilepsy, how epilepsy is diagnosed, and what to do if someone has a seizure.
Nair explains that seizures are a symptom, while epilepsy is a disease that causes recurrent epileptic seizures. Not every event that looks like a seizure is actually caused by epilepsy. For example, fainting — often due to a sudden drop in blood pressure — can resemble a seizure, but it’s not caused by abnormal brain activity. Some episodes called “nonepileptic seizures” are also unrelated to electrical disturbances in the brain.
Diagnosing epilepsy often begins with a detailed clinical history, including what a patient felt and what witnesses observed. Videos recorded on smartphones can be extremely helpful. To confirm the diagnosis, doctors may use EEG testing, which measures the brain’s electrical activity. While an EEG can detect abnormal electrical signals, a normal EEG doesn’t rule out epilepsy because the disease is intermittent. Imaging, such as high-resolution MRI scans, can identify structural changes in the brain that may contribute to seizures, but EEG remains the key diagnostic tool for epilepsy because it identifies functional abnormalities.
Nair also covers what to do if someone is having a seizure — using the “Three S’s” recommended by the Epilepsy Foundation:
- Stay with the person and time the seizure. If it lasts longer than three minutes, call 911.
- Side: Gently roll the person onto their side so saliva or vomit can drain safely.
- Safe: Keep the person safe by clearing the area. Do not restrain them or put anything in their mouth.
These steps help ensure safety during a seizure and prevent complications while waiting for the episode to pass or for emergency help if needed.
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