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What Is Epilepsy?

Epilepsy (pronounced: EH-puh-lep-see) nervous system condition that causes seizures. But having a seizure doesn't always mean that someone has epilepsy — many people who have one seizure never have another. But it’s considered epilepsy when a person keeps having seizures for no clear reason.

Many people develop epilepsy as children or teens. Others develop it later in life. For some people with epilepsy (especially kids), the seizures can happen less often over time or stop altogether.

What Are Seizures?

There are different kinds of seizures, but they all happen because of unusual electrical activity in the brain. Brain cells constantly send electrical signals that travel along nerves to the rest of the body. These signals tell the muscles to move so you can do your normal activities.

Seizures happen when electrical signals in the brain misfire. These overactive electrical discharges disrupt the brain's normal electrical activity and cause a temporary communication problem among nerve cells.

What Are the Signs of a Seizure?

It can be hard to know if someone is having an epileptic seizure. Sometimes, a person’s whole body will shake. Other times, a person might simply stare blankly into space for a few seconds. 

Someone having a seizure may:

  • lose consciousness
  • seem unaware of what's going on
  • make involuntary motions (movements the person has no control over, such as jerking or thrashing one or more parts of the body)
  • have unusual feelings or sensations (such as unexplained fear)

Seizures may look frightening, but they're not painful and most last only a few seconds or minutes. After a seizure, they might feel tired, weak, or confused for a few minutes or even an hour or more. People who've had seizures may not remember the seizure or what happened right before it. They may be alert and ready to go back to whatever they were doing before it happened. It varies from person to person.

What Are the Types of Epilepsy?

The type of epilepsy someone has depends on the seizure type. A seizure can be:

  • a generalized seizure, which involves both sides of the brain at once
  • a focal seizure, which involves only one side, but can spread to the other side (a secondary generalized seizure)

In a generalized seizure, electrical disturbances happen all over the brain at the same time. These include several types of seizures including absence seizures, tonic-clonic seizures, and myoclonic epilepsies.

Focal (or partial) seizures start in one part of the brain. The electrical disturbances may then move to other parts of the brain or they may stay in one area until the seizure is over.

Partial seizures can be either simple (where a person doesn't lose consciousness) or complex (where a person loses consciousness). There may be twitching of a finger or several fingers, a hand or arm, or a leg or foot. Some facial muscles might twitch. Speech might become slurred, unclear, or unusual during the seizure. The person's vision might be affected temporarily. They might feel tingling throughout one side of the body. It all depends on where in the brain the abnormal electrical activity is taking place.

What Causes Epilepsy?

Often, there’s no clear reason why someone has epilepsy. But some things can make a person more likely to develop it, including:

  • a brain injury or tumor
  • problems with the way the brain developed before birth
  • abnormal blood vessels in the brain
  • bleeding in the brain
  • meningitis, encephalitis, or any other type of infection that affects the brain

Epilepsy is not contagious (you can't catch it from someone who has it). It can run in families, but just because someone’s mom or dad or brother or sister has epilepsy, it doesn’t mean they will have it.

Some things can sometimes trigger seizures in people with epilepsy. They include:

  • flashing or bright lights
  • a lack of sleep
  • stress
  • overstimulation (like staring at a computer screen or playing video games for too long)
  • fever
  • some medicines
  • hyperventilation (breathing too fast or too deeply)

How Is Epilepsy Diagnosed?

Neurologists (pronounced: nuh-RAH-luh-jists) are doctors who find and treat nervous system problems. If you might have had a seizure, tell your doctor. They probably will want you to see a neurologist, who will check for epilepsy or other conditions.

The neurologist will do an exam and ask about things like your symptoms, your past health, and your family's health. This is called the medical history. Describe the seizure (or seizures) as best you can. Finding out what type of seizure a person has helps doctors decide how to treat it.

The neurologist might do medical tests such as an EEG test to measure the brain’s electrical activity. Brain scans, such as a CT scan or MRI test, may also be done. All these tests are painless.

How Is Epilepsy Treated?

Doctors usually treat epilepsy with medicines. If medicines don't control the seizures, sometimes they recommend a special diet, such as a ketogenic (pronounced: kee-toe-JEH-nik), or keto, diet. This strict high-fat, low-carbohydrate diet sometimes can make seizures happen less often.

For hard-to-control seizures, doctors may recommend vagus (pronounced: VAY-gus) nerve stimulation (VNS) with a device that stimulates the vagus nerve. This nerve runs up the sides of the neck and into the brain. The VNS sends electrical pulses to the nerve, which carries the pulses to the brain. This helps prevent or shorten the length of seizures.

Sometimes doctors might do surgery when other treatments can’t control the seizures.

What if I’m With Someone Who Has a Seizure?

To help someone who's having a seizure:

  • Stay calm.
  • Help, but don't force, the person to lie down on their side, preferably on a flat, comfortable surface.
  • Take the person's glasses or backpack off and loosen any tight clothing near the neck.
  • Don't restrain or hold the person.
  • Move objects, especially sharp or hard ones, away from the person.
  • Stay with the person or make sure another friend or trusted person stays with them.
  • Make sure your friend's breathing is OK.
  • Do not put anything into the person's mouth during a seizure. They won’t swallow their tongue, and forcing the mouth open may cause an injury.
  • Talk with the person in a calm, reassuring way after the seizure is over. If you can, tell them what happened before, during, and after the seizure.

Usually, there’s no need to call 911 if the person having a seizure is known to have epilepsy. But do call if the person is injured, has breathing problems, looks blue around the mouth, has another medical condition like diabetes, or has a long seizure (more than 5 minutes) or multiple seizures.

What Else Should I Know?

People with epilepsy can and do live normal lives. If you have epilepsy, you can still do regular activities, go on dates, and get a job. Your doctor will talk about being careful in some situations. For example, you can enjoy swimming, but should always swim with other people to be safe. If your epilepsy is under medical control, you’ll still be able to drive.

Tell the people close to you — friends, relatives, teachers, coaches — about your epilepsy and what to do if you have a seizure when they're with you. 

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Medically reviewed by: Amy W. Anzilotti, MD
Date reviewed: July 2021