Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier
WebMD

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine
WebMD

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion
    WebMD

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community
    WebMD

    Community

    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Epilepsy Health Center

Font Size
A
A
A

Understanding Seizures -- the Basics

What Are Seizures?

A seizure occurs when there’s abnormal electrical activity in the brain. Seizures may go virtually unnoticed. Or, in severe cases, they may produce a change or loss of consciousness and involuntary muscle spasms called convulsions. Seizures usually come on suddenly and vary in duration and severity. A seizure may be a one-time event, or you may have seizures repeatedly. Recurrent seizures are called epilepsy, or a seizure disorder. Less than one in 10 people who has a seizure develops epilepsy.

Experts classify seizures into two general categories and many subtypes based on the pattern of the attack.

Recommended Related to Epilepsy

Actor Greg Grunberg Steps Up for Epilepsy

On the NBC show Heroes, Greg Grunberg plays an ordinary guy with extraordinary powers. In real life, he credits astonishing powers to his 13-year-old son, Jake, who has lived with epilepsy for the past five years. Epilepsy, a neurological condition that affects 3 million Americans (350,000 of them are children), causes periodic seizures, where the brain produces a sudden burst of electrical activity. During a seizure, people can shake, stare, fall down, or even briefly lose consciousness. "To...

Read the Actor Greg Grunberg Steps Up for Epilepsy article > >

Generalized seizures involve both sides of the brain from the start of the attack. Common subtypes include tonic-clonic (grand mal) and absence seizures (petit mal). Febrile and infantile spasms are two types of generalized seizures that occur almost exclusively in young children.

Partial (or focal) seizures are the second major seizure type. These begin in a specific area of the brain and may be contained there. Or they may spread to the entire brain.

  • With simple partial seizures, the person remains conscious.
  • Complex partial seizures involve impaired consciousness.

What Causes Seizures?

Often the cause of a seizure is unknown. Many conditions can provoke seizures, including:

WebMD Medical Reference

Reviewed by Richard Senelick, MD on March 01, 2015

Today on WebMD

human head and brain waves
Causes, symptoms, and treatments.
Grand mal seizure
How is each one different?
 
marijuana plant
CBD, a plant chemical, may cut down seizures.
prescription bottle
Which medication is right for you?
 
Seizures Driving
Article
Questions for Doctor Epilepsy
Article
 
Graces Magic Diet
Article
Pills spilling from bottle in front of clock
Article
 
first aid kit
Article
Caring Child Epilepsy
Article
 
Making Home Safe
Article
epilepsy monitoring
Article