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What Is Epilepsy?

Epilepsy is a condition of the nervous system that affects 3 million Americans. More than 150,000 people are diagnosed with epilepsy every year.

It can be hard to know if someone is having an epileptic seizure. While some people have convulsions of their whole body, others simply stare blankly into space for a few seconds. The person may lose consciousness or 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), or experience unusual feelings or sensations (such as unexplained fear). After a seizure, he or she may feel tired, weak, or confused.

People have seizures when the 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.

Having a seizure doesn't always mean that a person has epilepsy. Seizures can be triggered in anyone under certain conditions, such as life-threatening dehydration or being severely overheated. But when a person experiences repeated seizures for no obvious reason, that person is said to have epilepsy.


What Causes Epilepsy?

This's no clear-cut answer to why people have epilepsy. Often doctors can't pinpoint the exact cause of a person's epilepsy. But scientists do know that some things can make a person more likely to develop epilepsy, including:

  • lack of oxygen to an infant's brain during childbirth
  • brain tumors or strokes
  • poisoning, such as drug abuse or lead or alcohol poisoning


Understanding Seizures



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. Certain facial muscles might twitch. Speech might become slurred, unclear, or unusual during the seizure. The person's vision might be affected temporarily. He or she might feel tingling throughout one side of the body. It all depends on where in the brain the abnormal electrical activity is taking place.

Generalized seizures involve electrical disturbances that occur all over the brain at the same time. These include several types of seizures including absence seizures (pronounced ab-SAHNTZ, also called petit mal), tonic-clonic seizures (also called grand mal), and myoclonic epilepsies. 

Absence seizures are more common in girls than in boys. In this type of seizure, the person may appear to be daydreaming or may stare off into space. After the seizure, which may last about 15 seconds or less, the person returns to their normal level of activity.

During a tonic-clonic seizure, a person’s eyes may roll back, the muscles may stiffen, and the person might make sudden jerking motions, such as flinging the arms outward. He or she may suddenly go limp and slump down or fall over. The person could also lose control of the bowel or bladder. 

Other types of seizures include myoclonic seizures and infantile spasms. Talk to your doctor to learn more or visit the Epilepsy Foundation website.



  • flashing or bright lights
  • a lack of sleep
  • stress
  • fever
  • certain medications
  • hyperventilation (breathing too fast or too deeply)

What Do Doctors Do?


In addition to doing a physical examination, the neurologist will ask you about any concerns and symptoms you have, your past health, your family's health, any medications you're taking, any allergies you may have, and other issues. This is called the medical history. It's important to give the most accurate description possible of the seizure (or seizures). Identifying the type of seizure a person has helps the doctor decide how to treat it. Because people who've had seizures may not remember anything about them, it's a good idea to get a detailed description from someone who saw it and write it down afterward.


If the neurologist determines that a person has epilepsy, he or she will recommend an appropriate type of treatment. Treatment for epilepsy usually involves medication, but sometimes other treatments can help. The goal of treatment is to control seizures so that a person can live as normally as possible. In some cases, doctors can implant a device called a vagus (pronounced: VAY-gus) nerve stimulator. This device sends signals through the vagus nerve in the neck to control seizures.


Living With Epilepsy





  • Stay calm.
  • Help, but don't force, the person to lie down on his or her side, preferably on a flat, comfortable surface.
  • Don't restrain or hold the person.
  • Make sure your friend's breathing is OK.
  • Don't put anything into the person's mouth during a seizure. Your friend won’t swallow his or her tongue, and forcing the mouth open may cause an injury.

There's usually no need to call 911 if the person having a seizure is known to have epilepsy. However, if the person is injured, is having breathing problems or appears bluish around the mouth, has another medical condition like diabetes, or has a long seizure (more than 5 minutes) or multiple seizures, he or she may need medical attention.


Date reviewed: June 2016