A seizure is the physical changes in behavior that occurs during an episode of abnormal electrical activity in the brain.
The term "seizure" is often used interchangeably with "convulsion." During convulsions a person has uncontrollable shaking that is rapid and rhythmic, with the muscles contracting and relaxing repeatedly. There are many different types of seizures. Some have mild symptoms without shaking.
Secondary seizures; Seizure - secondary; Convulsions; Epileptic seizure
It may be hard to tell if someone is having a seizure. Some seizures only cause a person to have staring spells. These may go unnoticed.
Specific symptoms depend on which part of the brain is involved. Symptoms occur suddenly and may include:
Symptoms may stop after a few seconds or minutes, or continue for up to 15 minutes. They rarely continue longer.
The person may have warning symptoms before the attack, such as:
Seizures of all types are caused by abnormal electrical activity in the brain.
Causes of seizures can include:
Sometimes, no cause can be found. This is called idiopathic seizures. They are usually seen in children and young adults, but can occur at any age. There may be a family history of epilepsy or seizures.
If seizures continue repeatedly after the underlying problem is treated, the condition is called epilepsy.
Most seizures stop by themselves. But during a seizure, the person can be hurt.
When a seizure occurs, the main goal is to protect the person from injury:
Things friends and family members should NOT do:
If a baby or child has a seizure during a high fever, cool the child slowly with lukewarm water. DO NOT place the child in a cold bath. Call your child's health care provider and ask what you should do next. Also, ask if it is OK to give the child acetaminophen (Tylenol) once they are awake.
Contact 911 or the local emergency number if:
Report all seizures to the person's provider. The provider may need to adjust or change the person's medicines.
A person who has had a new or severe seizure is usually seen in a hospital emergency room. The provider will try to diagnose the type of seizure based on the symptoms.
Tests will be done to rule out other medical conditions that cause seizures or similar symptoms. This may include fainting, transient ischemic attack (TIA) or stroke, panic attacks, migraine headaches, sleep disturbances, and other possible causes.
Tests that may be ordered include:
Further testing is needed if a person has:
Krumholz A, Wiebe S, Gronseth GS, et al. Evidence-based guideline: management of an unprovoked first seizure in adults: report of the Guideline Development Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2015;84(16):1705-1713. PMID: 25901057 pubmed.ncbi.nlm.nih.gov/25901057/.
Maciel CB, Elie-Turrene M-C. Seizure. In: Walls RM, ed. Rosen's Emergency Medicine: Concepts and Clinical Practice. 10th ed. Philadelphia, PA: Elsevier; 2023:chap 92.
Mikati MA, Tchapyjnikov D. Seizures in childhood. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 611.
Templer JW, Schuele SU. Diagnosis and classification of seizures and epilepsy. In: Winn HR, ed. Youmans and Winn Neurological Surgery. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 80.
Reviewed By: Joseph V. Campellone, MD, Department of Neurology, Cooper Medical School at Rowan University, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.