Overview

A grand mal seizure causes a loss of consciousness and violent muscle contractions. It's the type of seizure most people picture when they think about seizures.

A grand mal seizure — also known as a generalized tonic-clonic seizure — is caused by abnormal electrical activity throughout the brain. Usually, a grand mal seizure is caused by epilepsy. But sometimes, this type of seizure can be triggered by other health problems, such as extremely low blood sugar, a high fever or a stroke.

Many people who have a grand mal seizure never have another one and don't need treatment. But someone who has recurrent seizures may need treatment with daily anti-seizure medications to control and prevent future grand mal seizures.