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Medically reviewed by Last updated on Feb 5, 2024.

What is Epilepsy?

Harvard Health Publishing

Epilepsy is a brain condition that causes repeated episodes of sudden, brief changes in the brain’s electrical activity. These changes cause various types of symptoms.

Epileptic episodes are called seizures or convulsions. During a seizure, brain cells fire uncontrollably at up to four times their normal rate. Seizures temporarily affect the way a person behaves, moves, thinks or feels.

There are two main types of seizures:

A combined generalized and focal seizureThere are two other much less common types of seizures:

Many conditions can affect the brain and trigger epilepsy. These include:

In most people with epilepsy, the specific cause is unknown.


The symptoms of epilepsy vary. They depend on how much of the brain is affected, and where the affected area is located.

Primary generalized seizures:

The seizure episode may last for a few minutes, during which a person is unconscious. When someone wakes up from a generalized tonic-clonic seizure, they are lethargic and confused. This usually lasts minutes, but it can last hours. There may be muscle soreness and a headache.

This type of seizure usually begins in childhood or early adolescence.

Simple partial seizure —The person remains awake and aware. Symptoms vary depending on the brain area involved. They can include:

After the seizure, the person has no memory of the episode.

Status epilepticus —Occurs when a person has a generalized seizure that lasts long enough to raise the risk of death, or recurs without full return to consciousness.  Status epilepticus used to be defined by a generalized seizure that lasted 30 minutes or more. Today, it is defined by one of two features:

Status epilepticus is a life-threatening medical emergency that requires immediate medical attention.


You may not have any seizure symptoms when you visit your doctor's office. For this reason, it is important to enlist the help of anyone who has witnessed your seizure. Ask that person to describe exactly what they saw: what happened at the start, what happened next. Write this description down for your doctor. This description will help your doctor determine the type of seizure you had. It will also help to decide on appropriate treatment.

Having a seizure does not mean that a person has epilepsy. For example, it's common for children to have seizures associated with fever. Most children who have them do not develop epilepsy.

Your doctor will diagnose epilepsy based on:

In many cases, your doctor will also order a computed tomography (CT) scan or magnetic resonance imaging (MRI) scan of the brain. Other types of brain scans also may be needed.

Your doctor may want to check whether your seizures are related to causes outside the brain. To do so, he or she may order basic lab tests. These can include blood tests, urinalysis and an electrocardiogram (EKG).

Expected Duration

Epilepsy can be a lifelong condition. But many people with a history of multiple seizures eventually will stop having seizures.

People who are younger when seizures start are more likely to stop having seizures. The same is true for people who have a normal neurological examination.

For most people with epilepsy, seizures can be controlled with medication.


The cause of most cases of epilepsy remains unknown. Therefore, there is no way to prevent the condition.  

However, there is very effective treatment for people with epilepsy that can reduce the number and severity of seizures. For many, control of epilepsy can prevent almost all seizures from occurring.

To help prevent epilepsy caused by head injury, you can:

Anyone with an active seizure disorder should take precautions. These will minimize the risk of injury if a seizure should occur. For this reason, people with epilepsy are advised not to operate a motor vehicle for at least six months after the most recent seizure. The same applies to operating other dangerous machinery.

People with epilepsy should consider wearing some sort of medical identification that describes their condition. This will provide important information to emergency medical personnel.


In most cases, treatment begins with one of the many anti-epileptic medications. The type of medication used depends on the type of seizure being treated.

When medication fails to control a person's seizures, surgery may be considered. If the abnormal electrical activity that triggers each seizure is coming from one particular part of the brain, cutting out that part of the brain can stop the repeated seizures. Of course this kind of brain surgery can cause some permanent problems with brain function, depending on where in the brain the focus of the seizures is. For this reason, the risks of surgery have to be balanced against the benefits. The decision to perform surgery depends on many factors. These include:

Status epilepticus is a life-threatening medical emergency. It is treated with medications given intravenously or rectally. Protective measures are also taken. These measures keep the person's airway open. And they help to prevent injury to the person's head and tongue.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

View more treatment options

When To Call A Professional

Call your doctor whenever you or anyone in your family experiences new symptoms suggestive of a seizure.  

Call for emergency help immediately if you suspect that someone with epilepsy has developed status epilepticus.


Most people with epilepsy can control their seizures with medication.

Some people have epilepsy that cannot be controlled with anti-epileptic drugs. Many of these cases can be treated with surgery.

Additional Info

American Epilepsy Society

Epilepsy Foundation


Learn more about Epilepsy

Treatment options

Care guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.