by EBSCO Medical Review Board

Epilepsy causes brief changes in the electrical activity of the brain. Clumps of nerve cells in the brain (neurons) message each other in a way that is not normal. These are called seizures.

The neurons fire as many as 500 times per second instead of about 80 times per second. This can cause strange feelings, emotions, and actions. It can also cause shaking, muscle spasms, and loss of consciousness.

Neurons in Nerve Tissue
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The diagnosis is made after a person has a seizure more than one time without a cause that could have been prevented.

Epilepsy may be from:

  • A problem with your nerves and blood vessels:
  • Brain or gene problems found at birth
  • Growths, such as brain tumors
  • A breakdown of the nervous system in the brain, such as Alzheimer disease
  • Some health problems:
  • Problems with the body's immune system:
    • NMDA receptor encephalitis and health problems like it
    • Paraneoplastic syndromes from cancer
    • Vasculitis, which can happen with problems like lupus
  • Any problem that keeps oxygen from the brain, such as near drowning
  • Diseases that can spread, such as:
  • Hydrocephalus—too much fluid in the brain
  • Celiac disease—an immune disorder in which people cannot eat wheat gluten
  • Exposure to:
  • Certain illegal drugs , such as cocaine , amphetamines, and phencyclidine
  • Overdose of antidepressants and other medicines
  • Withdrawal from alcohol, sedatives, and hypnotics
  • Certain medicines can raise the risk of seizures, such as:
    • Tricyclics
    • Theophylline
    • Penicillin
    • Phenothiazine
  • In children:
    • High fever
    • Infections
    • Not eating the right foods
    • Not enough vitamin B6 in newborns and infants
    • Lead poisoning
    • Hereditary, including genetic and metabolic problems

In many people, the cause is not known.

What are the risk factors for epilepsy?What are the symptoms of epilepsy?How is epilepsy diagnosed?What are the treatments for epilepsy?How can I reduce my risk of epilepsy?What questions should I ask my doctor?Where can I get more information about epilepsy?


Epilepsy in adults. EBSCO DynaMed website. Available at: Accessed April 7, 2022.

Epilepsy in children. EBSCO DynaMed website. Available at: Accessed April 7, 2022.

Epilepsy information page. National Institute of Neurological Disorders and Stroke website. Available at: Accessed April 7, 2022.

Seizure disorders. Merck Manual Professional Version website. Available at: Updated November 2018. Accessed April 7, 2022.

What is epilepsy? Epilepsy Foundation website. Available at: Accessed April 7, 2022.

Revision Information

  • Reviewer: EBSCO Medical Review Board Rimas Lukas, MD
  • Review Date: 03/2022
  • Update Date: 04/07/2022