Tonic-clonic seizure

Other names: Seizure, grand mal


A grand mal seizure — also known as a generalized tonic-clonic seizure — features a loss of consciousness and violent muscle contractions. It's the type of seizure most people picture when they think about seizures in general.

Grand mal seizure is caused by abnormal electrical activity throughout the brain. Most of the time grand mal seizure is caused by epilepsy. In some cases, however, this type of seizure is triggered by other health problems, such as extremely low blood sugar, high Fever or a Stroke.

Many people who have a grand mal seizure will never have another one. However, some people need daily anti-seizure medications to control and prevent future grand mal seizure.


Grand mal seizures have two stages:

The following signs and symptoms occur in some but not all people with grand mal seizures:

When to see a doctor

If you see someone having a seizure:

A grand mal seizure lasting more than five minutes, or immediately followed by a second seizure, should be considered a medical emergency in most people. Seek emergency care as quickly as possible.

Additionally, seek medical advice for you or your child when the number of seizures experienced increases significantly without explanation or when new signs or symptoms of seizures appear.


Grand mal seizures occur when the electrical activity over the whole surface of the brain becomes abnormally synchronized. The brain's nerve cells normally communicate with each other by sending electrical and chemical signals across the synapses that connect the cells.

In people who have seizures, the brain's usual electrical activity is altered. Exactly what causes the changes to occur remains unknown in about half the cases.

However, grand mal seizures are sometimes caused by underlying health problems such as injury or infection, congenital or developmental abnormalities, metabolic disturbances, and withdrawal syndromes.


Risk factors for grand mal seizures include:


Certain activities could be dangerous if you have a seizure while doing them. Activities include swimming, bathing, driving a car or operating other equipment. The force of a seizure or falling as a result of a seizure can cause injury.

Repeated seizures can lead to changes in brain function and structure. The seriousness of repeated seizures underscores the need for control with medication.


You're likely to start by seeing your family doctor or a general practitioner. However, you'll probably be referred to a doctor who specializes in nervous system disorders (neurologist).

It's good to be prepared for your appointment. Here's some information to help you get ready for your appointment and know what to expect from your doctor.


Your doctor will ask for a detailed description of the seizure which is crucial for diagnosis. A neurological exam may be performed along with blood tests and scans like an EEG or brain imaging.


Treatment usually involves anti-seizure medications which can vary based on individual needs and responses. It's important to follow your doctor's instructions regarding medication usage and dosage.


If you have a seizure disorder, wear a medical bracelet with relevant information in case of emergencies.


Seizures can affect your life even after they're under control. It may be helpful to seek support from groups like the Epilepsy Foundation that offer advice and coping strategies.


  1. What is another name for grand mal seizure?

Generalized tonic-clonic seizure.

  1. What are some symptoms that may occur before a grand mal seizure?


  1. When should you consider a grand mal seizure a medical emergency?

If it lasts more than five minutes or is immediately followed by another seizure.

  1. What are some risk factors for grand mal seizures?

Family history of seizure disorders, brain injuries, sleep deprivation, etc.

  1. What complications can arise from having seizures?

Injuries like dislocations, head injuries, bone fractures.

  1. How can repeated seizures affect the brain?

They can lead to changes in brain function and structure.

  1. What tests are commonly used for diagnosing seizures?

Neurological exam, blood tests, EEG, brain imaging.

  1. What is typically involved in treating seizures?

Anti-seizure medications.

  1. How can lifestyle changes help manage seizures?

Wearing a medical bracelet with relevant information.

  1. Where can individuals find support for coping with seizures?

Organizations like the Epilepsy Foundation offer support groups and online forums.