May also be called: Grand Mal Seizure A tonic-clonic seizure is a sudden attack that brings on intense muscle spasms and loss of consciousness. It is caused by abnormal electrical activity in the brain and affects the entire body. More to Know A tonic-clonic seizure can happen at any age. It's most commonly associated with epilepsy but can also be caused by low blood sugar, stroke, infections, traumatic head injuries, drug and alcohol withdrawal, and other underlying conditions. It can be a one-time or recurring event. Often, an aura (vision, taste, smell, or sensory changes) will signal an oncoming seizure. A tonic-clonic seizure occurs in two phases and usually only lasts for a few minutes. First, loss of consciousness occurs. This is followed by convulsions, or violent muscle contractions. The person may also bite the cheek or tongue, lose bladder or bowel control, clench the teeth or jaw, or have a blue skin color. Following the seizure, a person will probably be sleepy and confused with no memory of the event. A severe headache afterward is also common. It may take a few hours before the person starts feeling normal. Keep in Mind Anyone experiencing a tonic-clonic seizure should seek medical help. Treatment will depend upon the cause and often includes the use of anti-seizure medications. While medications can minimize the effects of seizures, living with chronic seizures can still be frightening and disruptive to daily life. Support groups and online forums are valuable resources for people with epilepsy and other seizure disorders. All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts. Back to Articles Related Articles Brain and Nervous System The brain controls everything we do, and is often likened to the central computer within a vast, complicated communication network, working at lightning speed. Read More Epilepsy It comes from a Greek word meaning "to hold or seize," and seizures are what happen to people with epilepsy. Learn more about epilepsy in this article written just for kids. Read More Epilepsy Epilepsy causes electrical signals in the brain to misfire, which can lead to multiple seizures. Anyone can get epilepsy at any age, but most new diagnoses are in kids. Read More Epilepsy Seizures are a common symptom of epilepsy, a condition that affects millions of people worldwide. Learn all about epilepsy, including what to do if you see someone having a seizure. Read More Febrile Seizures Febrile seizures are full-body convulsions caused by high fevers that affect young kids. Although they can be frightening, they usually stop on their own and don't cause any other health problems. Read More Seizures Seizures are caused by a sudden surge of electrical activity in the brain. Find out what you need to know about seizures and what to do if your child has one. Read More First Aid: Seizures Although seizures can be frightening, usually they last only a few minutes, stop on their own, and are almost never life-threatening. Read More When Blood Sugar Is Too Low Hypoglycemia is the medical word for low blood sugar level. It needs to be treated right away. Learn more about what to do when blood sugar is too low in this article for kids. Read More Word! Seizure You might hear a seizure called a convulsion, fit, or spell. Read More Hypoglycemia When blood glucose levels drop too low, it's called hypoglycemia. Very low blood sugar levels can cause severe symptoms that require immediate treatment. Read More What Is Hypoglycemia? Lots of people wonder if they have hypoglycemia, but the condition is not common in teens. Get the facts on hypoglycemia. Read More When Blood Sugar Is Too Low When blood glucose levels drop too low, it's called hypoglycemia. Very low blood sugar levels can cause severe symptoms that need to be treated right away. Read More Strokes This "brain attack" happens when blood flow to the brain stops, even for a second. Often, kids who have a stroke can learn to use their arms and legs and speak again through brain retraining. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.