Medical Term Definition

Seizure

A seizure is a temporary episode of abnormal, excessive, or synchronized electrical activity in the brain that can cause changes in movement, sensation, awareness, behavior, or consciousness.

Seizures vary widely. Some involve generalized stiffening and rhythmic jerking of the body, while others cause brief staring, unusual sensations, involuntary movements, confusion, or periods of reduced awareness. Not every seizure involves shaking or complete loss of consciousness.

Seizures can occur for several reasons, including epilepsy, fever in young children, low blood glucose, certain infections, head injuries, stroke, medication effects, or severe disturbances in the body’s chemical balance. A person can have a seizure without having epilepsy, which is a neurological condition characterized by an enduring tendency to experience recurrent unprovoked seizures.

During a seizure, protect the person from nearby hazards, cushion the head if possible, and move dangerous objects away. Do not restrain the person’s movements or put anything in their mouth. When the convulsions stop, place the person on their side if they are unconscious but breathing normally, and monitor their breathing.

Seek emergency medical assistance if a seizure lasts five minutes or longer, another seizure begins before the person recovers, the person has difficulty breathing or waking afterward, the seizure occurs in water, or it is the person’s first known seizure. A seizure associated with suspected heatstroke is also an emergency.

QUICK FACT

A person cannot swallow their tongue during a seizure. Putting fingers, spoons, or other objects into the mouth can cause injury or obstruct breathing.

COMMONLY CONFUSED WITH

  • Epilepsy: A neurological disorder involving an enduring predisposition to recurrent unprovoked seizures. A single seizure does not automatically mean a person has epilepsy.
  • Fainting: A brief loss of consciousness caused by a temporary reduction in blood flow to the brain. Fainting can sometimes involve brief jerking movements, making it resemble a seizure.
  • Heatstroke: A medical emergency caused by dangerous overheating that can trigger seizures and other neurological symptoms.

SEE ALSO

Clinical & Educational Context

Discussed in Health Articles & Guides

Explore how "Seizure" is covered across our evidence-based editorial guides:

3 Articles
The Hard Parts of Medicine

Polypharmacy: What Really Happens When You Take Multiple Medicines

Seizures, collapse, or sudden marked confusion.
Medicine without Jargon

The Best Birthing Position: What Current Evidence Says

Heavy vaginal bleeding, severe abdominal pain between contractions, loss of consciousness, seizures, or persistent concerns about the baby's heart rate require immediate medical assessment.
Cases & Narratives

His Last Malaria: A Case of Suspected Fake Medicines

Seek urgent medical care if someone with suspected or confirmed malaria develops worsening symptoms, confusion, unusual drowsiness, difficulty breathing, repeated vomiting, inability to drink...