How Do I Know If I Have Epilepsy?

Medically Reviewed by Christopher Melinosky, MD on March 06, 2024
3 min read

An epilepsy diagnosis takes patience. It isn’t something that happens in one office visit. But if you stick with the process, your doctor can figure out if the disease is causing your seizures and treat it.

Whether you have epilepsy depends on your symptoms before, during, and after a seizure. Since the doctor probably won’t be there when you have one, they’ll run a number of tests and ask many questions to reach a diagnosis.

To figure out if you have epilepsy and what type you have, your doctor will do some or all of these tests:

Electroencephalogram (EEG). This is the most common test. Your doctor places sensors on your scalp that record electrical activity in your brain. If they see changes in your normal brain wave pattern, that’s a symptom. Many people with epilepsy have abnormal EEGs.

You can have this test while you’re asleep or awake. The doctor may watch you on video to record how your body reacts during a seizure. This usually requires an overnight stay or two at the hospital.

Computerized tomography (CT) scan. It uses X-rays to create images of your brain. This can help your doctor rule out other seizure causes, like tumors, bleeding, and cysts.

Blood tests. They also help discount other reasons for seizures, like genetic conditions or infections.

Magnetic resonance imaging (MRI). It lets your doctor see the structure of your brain. It may show damaged tissue that leads to seizures. For the test, you’ll lie on a table inside the MRI machine, which is like a tunnel. The scanner takes pictures of the inside of your head.

Functional MRI (fMRI). This type of MRI shows which part of your brain uses more oxygen when you speak, move, or do certain tasks. That helps your doctor avoid those areas if they need to operate on your brain.

Magnetic resonance spectroscopy (MRS). Like the MRI, an MRS creates an image. It helps the doctor compare how different parts of your brain work. Unlike the MRI, it doesn’t show your entire brain at once. It focuses only on the parts of the brain your doctor wants to study more.

Positron emission tomography (PET scan). For this test, the doctor injects a radioactive material into a vein in your arm. It then collects in your brain. This helps check for damage by showing which parts of your brain use more or less glucose. The PET scan helps your doctor see changes in your brain chemistry and find problems.

Single-photon emission computerized tomography (SPECT). This two-part test helps your doctor figure out where seizures start in your brain. As with the PET scan, the doctor injects a small amount of radioactive material into a vein to show blood flow. They’ll repeat the test when you aren’t having a seizure and compare the difference between the scans.

Neuropsychological tests. The doctor will test your speech, thinking, and memory skills to see if those areas of your brain have been affected by seizures.

Your doctor needs to learn all they can about your seizures. They’ll ask questions about them and about your medical history. It helps to bring someone with you who’s seen you have a seizure to help answer these questions:

  • How old were you when the seizures began?
  • What sets off a seizure? Does it happen when you’re tired, stressed, or hungry?
  • How did you feel, physically and emotionally, before the seizure?
  • Did you notice an odd smell or taste before it started?
  • During the seizure, did you pass out or feel confused?
  • Did you mumble or were you able to speak?
  • Did your skin color or breathing change?
  • Did you fall down, twitch, or go limp?
  • How long did it last?
  • How did you feel after it ended? Were you tired?
  • How long was it until you felt normal again?