Skip to content

Epilepsy: Generalized Tonic-Clonic Seizures

Make an Appointment

Our team is here to help you make an appointment with the specialists that you need.

Epilepsy: Generalized Tonic-Clonic Seizures

Overview

Generalized tonic-clonic (grand mal) seizures are the easiest seizures to recognize. They happen most often in people with generalized epilepsy of unknown cause.

A generalized tonic-clonic seizure begins with a sudden loss of consciousness. During the first 15 to 30 seconds of the seizure, the entire body stiffens as the muscles contract. The back and neck are arched. Sometimes the person may cry out as the vocal cords contract and air is released from the lungs. The person may turn blue because he or she isn't breathing. This is the tonic phase of the seizure.

During the next 30 to 45 seconds, the muscles jerk (convulse) in a rhythmic pattern. This is the clonic phase of the seizure. While the muscles are jerking, the person may bite his or her tongue or lose bladder or bowel control.

An entire seizure lasts 1 to 2 minutes. After the seizure, the person will be unresponsive at first but will gradually wake up in 10 to 30 minutes. The person may be sleepy, confused, or dazed. The person may also feel tired, weak, or moody and may have a headache and muscle aches for the next 24 hours.

Related Information

Credits

Current as of: May 1, 2023

Author: Healthwise Staff
Clinical Review Board
All Healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.