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Generalized Tonic Clonic Seizures

Medically reviewed by Last updated on Dec 4, 2023.

What are generalized tonic-clonic seizures?

A generalized tonic-clonic seizure may also be called a grand mal seizure. A seizure means an abnormal area in your brain sometimes sends bursts of electrical activity. A generalized seizure affects both sides of your brain. Tonic and clonic are phases that happen during the seizure. The tonic phase causes your muscles to become stiff. You lose consciousness and may fall down. The clonic phase causes convulsions (repeated muscle contractions). A seizure may last from a few seconds up to 3 minutes. It is an emergency if it lasts longer than 5 minutes.

What increases my risk for tonic-clonic seizures?

  • Epilepsy
  • A family history of epilepsy or seizures
  • A brain injury, head trauma, infection, tumor, or stroke
  • Blood vessel problems in the brain
  • A lack of sleep
  • Very low glucose (sugar), sodium (salt), calcium, or magnesium levels
  • Withdrawal from drugs or alcohol

What are the signs and symptoms of a tonic-clonic seizure?

  • Sudden loss of consciousness
  • Convulsions
  • Crying out
  • Not responding when spoken to
  • Biting your lips or cheeks
  • Loss of bladder control
  • Confusion and lack of energy after the seizure stops

How are tonic-clonic seizures diagnosed?

Your healthcare provider will ask about your health conditions and what medicines you take. Epilepsy is usually diagnosed if you have at least 2 seizures within 24 hours. It may also be diagnosed if you have 1 seizure but are likely to have more. A brain scan or electroencephalogram (EEG) may also show signs of epilepsy that make another seizure likely. Tell the provider how close together the seizures were if you had more than one. Your healthcare provider will ask for a detailed description of each seizure. If possible, bring someone with you who saw you have a seizure. You may also need any of the following:

  • Blood tests may show the cause of your seizures. The tests may be used to check your blood glucose, sodium, calcium, or potassium levels.
  • An EEG records the electrical activity of your brain. It is used to find changes in the normal patterns of your brain activity.
  • CT or MRI pictures may be used to check for injuries or abnormal areas in your brain. You may be given contrast liquid to help your brain show up better in the pictures. Tell the healthcare provider if you have ever had an allergic reaction to contrast liquid. Do not enter the MRI room with anything metal. Metal can cause serious injury. Tell the healthcare provider if you have any metal in or on your body.
  • A PET scan is used to see activity in areas of your brain. You are given radioactive material that helps healthcare providers see the activity better.
  • A SPECT scan uses radioactive material to find where the seizure started in your brain. This scan may be done if other scans do not show where the seizure started.

How are tonic-clonic seizures treated?

Your healthcare provider may treat any health conditions causing your seizures. The goal of treatment is to try to stop your seizures completely. You may need any of the following:

  • Medicines may be given to treat certain health conditions. You may need antiepileptic medicine if your seizures are caused by epilepsy. You may need medicine daily to prevent seizures or during a seizure to stop it. Do not stop taking your medicine unless directed by your healthcare provider.
  • Surgery may help reduce how often you have seizures if you have epilepsy and medicine does not help. Ask your healthcare provider for more information about surgery for epilepsy.

Treatment options

The following list of medications are in some way related to or used in the treatment of this condition.

View more treatment options

What can I do to prevent a tonic-clonic seizure?

You may not be able to prevent every seizure. The following can help you manage triggers that may make a seizure start:

  • Take antiseizure medicine every day at the same time. This will also help prevent medicine side effects. Set an alarm to help remind you to take your medicine every day. If you are a woman, talk to your provider about family planning while you are taking this medicine.
  • Manage stress. Stress can be a trigger for epilepsy. Exercise can help you reduce stress. Talk to your healthcare provider about exercise that is safe for you. Illness can be a form of stress. Eat a variety of healthy foods and drink plenty of liquids during an illness. Talk to your healthcare provider about other ways to manage stress.
  • Set a regular sleep schedule. A lack of sleep can trigger a seizure. Try to go to sleep and wake up at the same time every day. Keep your bedroom quiet and dark. Talk to your healthcare provider if you are having trouble sleeping.
  • Limit or do not drink alcohol as directed. Alcohol can trigger a seizure, especially if you drink a large amount at one time. A drink of alcohol is 12 ounces of beer, 1½ ounces of liquor, or 5 ounces of wine. Talk to your healthcare provider about a safe amount of alcohol for you. Your provider may recommend that you do not drink any alcohol. Tell him or her if you need help to quit drinking.

What can I do to manage tonic-clonic seizures?

The following can help you manage the seizures if you have more than one:

  • Keep a seizure diary. This can help you find your triggers and avoid them. Possible triggers include illness, lack of sleep, hormone changes, alcohol, drugs, lights, and stress. Write down the dates of your seizures, where you were, and what you were doing. Include how you felt before and after.
  • Record any auras you have before a seizure. An aura is a sign that you are about to have a seizure. Auras happen before certain types of seizures that are in only 1 part of the brain. The aura may happen seconds before a seizure, or up to an hour before. You may feel, see, hear, or smell something. Examples include part of your body becoming hot. You may see a flash of light or hear something. You may have anxiety or déjà vu. If you have an aura, include it in your seizure diary.
  • Create a care plan. Tell family, friends, and coworkers about your epilepsy. Give them instructions that tell them how they can keep you safe if you have a seizure.
  • Ask what safety precautions you should take. Talk with your healthcare provider about driving. You may not be able to drive until you are seizure-free for a period of time. You will need to check the law where you live. Also talk to your healthcare provider about swimming and bathing. You may drown or develop life-threatening heart or lung damage if you have a seizure in water.
  • Carry medical alert identification. Wear medical alert jewelry or carry a card that says you have tonic-clonic seizures. Ask your healthcare provider where to get these items.
    Medical Alert Jewelry

What do I need to know about stopping my medicine?

Your healthcare provider can help you understand and make decisions about continuing or stopping antiseizure medicines. Do not stop taking the medicine until your provider says it is okay. You may need to be seizure free for 18 to 24 months before you can stop your medicine. Seizures might happen again while you stop taking the medicine, or after you stop. Rarely, these seizures no longer respond to medicines. Tests such as an EEG may be useful in helping you and your provider make medicine decisions.

How can others keep me safe during a seizure?

Give the following instructions to family, friends, and coworkers:

  • Do not panic.
  • Do not hold me down or put anything in my mouth.
  • Gently guide me to the floor or a soft surface.
  • Place me on my side to help prevent me from swallowing saliva or vomit.
    First Aid: Seizures (ADULT)
  • Protect me from injury. Remove sharp or hard objects from the area surrounding me, or cushion my head.
  • Loosen the clothing around my head and neck.
  • Time how long my seizure lasts. Call 911 if my seizure lasts longer than 5 minutes or if I have a second seizure.
  • Stay with me until my seizure ends. Let me rest until I am fully awake.
  • Perform CPR if I stop breathing or you cannot feel my pulse.
  • Do not give me anything to eat or drink until I am fully awake.

Call your local emergency number (911 in the US), or have someone else call, for any of the following:

  • This is the first seizure you have ever had.
  • You have trouble breathing or feeling alert after a seizure.
  • The seizure lasts longer than 5 minutes.
  • You had a seizure in water, such as in a swimming pool or hot tub.
  • You have diabetes or are pregnant and had a seizure.

When should I call my doctor?

  • You have a second seizure within 24 hours of the first.
  • You are injured during a seizure.
  • You feel you are not able to cope with your condition.
  • Your seizures start to happen more often.
  • You are confused longer than usual after a seizure.
  • You are planning to get pregnant or are currently pregnant.
  • You have questions or concerns about your condition or care.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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Further information

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