Topic Overview

The brain controls how the body moves by sending out small electrical signals through the nerves to the muscles. Seizures, or convulsions, occur when abnormal signals from the brain change the way the body functions.

Seizures are different from person to person. Some people have only slight shaking of a hand and do not lose consciousness. Other people may become unconscious and have violent shaking of the entire body.

Shaking of the body, either mild or violent, does not always occur with seizures. Some people who have seizures briefly lose touch with their surroundings and appear to stare into space. Although the person is awake, he or she does not respond normally. Afterwards, the person does not remember the episode.

Not all body shaking is caused by seizures. Many medical conditions can cause a type of body shaking that usually affects the hands and head (tremors).

A small number of people will have only one seizure during their lifetime. A single seizure usually lasts less than 3 minutes and is not followed by a second seizure. Any normally healthy person can have a single seizure under certain conditions. For instance, a sharp blow to the head may cause a seizure. Having one seizure does not always mean that a serious health problem exists. But if you have a first-time seizure, you should be checked by your doctor. It is important to rule out a serious illness that may have caused the seizure. Fever seizures (febrile convulsions) are the most common cause of a single seizure, especially in children. For more information, see the topic Fever Seizures.

Causes of seizures

Epilepsy is a nervous system problem that causes seizures. It can develop at any age. About 2.5 million Americans have epilepsy. For more information, see the topic Epilepsy.

A seizure can be a symptom of another health problem, such as:

• A rapidly increasing fever (fever seizure).
• An extremely low blood sugar level in a person who has diabetes.
• Damage to the brain from a stroke, brain surgery, or a head injury.
• Problems that have been present since birth (congenital problems).
• Withdrawal from alcohol, prescription medicine, or illegal drugs.
• An infection, such as meningitis or encephalitis.
• A brain tumor or structural defect in the brain, such as an aneurysm.
• Parasitic infections, such as tapeworm or toxoplasmosis.

Eclampsia is pregnancy-related seizure activity that is usually caused by high blood pressure. It is a life-threatening condition for both a mother and her baby (fetus) because during a seizure, the fetus's oxygen supply is drastically reduced. Eclampsia is more likely to occur after the 20th week of pregnancy. For more information, see the topic Preeclampsia and High Blood Pressure During Pregnancy.

Nonepileptic seizure (NES), also called pseudoseizure, is a condition that can cause seizure-like activity. NES is characterized by a loss of or change in physical function without a central nervous system problem. The loss or change causes periods of physical activity or inactivity that resemble epileptic seizures. NES is usually related to a mental health problem. The physical symptoms may be caused by emotional conflicts or stress. The symptoms usually appear suddenly and at times of extreme emotional stress.

Protect a person during a seizure

No matter what caused the seizure, you can take steps to protect a person during a seizure and to get help after the seizure.

• During a seizure:
  • Protect the person from injury.
    • Keep him or her from falling if you can, or try to guide the person gently to the floor.
    • Try to move furniture or other objects that might injure the person during the seizure.
    • If the person is having a seizure and is on the ground when you arrive, put something soft under his or her head.
  • Do not force anything, including your fingers, into the person's mouth. Putting something in the person's mouth may cause injuries to him or her, such as chipped teeth or a fractured jaw. You could also get bitten.
  • Turn the person onto his or her side, with the mouth down, unless the person resists being moved.
  • Do not try to hold down or move the person.
  • Try to stay calm.
  • If the person vomits, turn the person onto his or her side.
  • Pay close attention to what the person is doing so that you can describe the seizure to rescue personnel or doctors.
    • What kind of body movement occurred?
    • How long did the seizure last?
    • How did the person act immediately after the seizure?
    • Are there any injuries from the seizure?
  • Time the length of the seizure, if possible.
• After a seizure:
  • Check the person for injuries.
  • If you could not turn the person onto his or her side during the seizure, do so when the seizure ends and the person is more relaxed.
  • If the person is having trouble breathing, use your finger to gently clear his or her mouth of any vomit or saliva.
  • Loosen tight clothing around the person's neck and waist.
  • Provide a safe area where the person can rest.
  • Do not give anything to eat or drink until the person is fully awake and alert.
  • Stay with the person until he or she is awake and familiar with the surroundings. Most people will be sleepy or confused after a seizure.

A person who has had a seizure should not drive, swim, climb ladders, or operate machinery until he or she has seen a doctor about the seizure.

Treatment

Treatment of a seizure depends on what has caused the seizure.

Use the Check Your Symptoms section to decide if and when you should see a doctor.