Overview

What is a tonic-clonic (grand mal) seizure?

A tonic-clonic seizure is a type of seizure that causes strong muscle movements on both sides of your body, including convulsions. These are typically the best known and easiest to recognize seizures because of these movements.

Tonic-clonic seizures were formerly known as “grand mal” seizures, from the French phrase meaning “great illness.” The term “tonic-clonic” refers to the two phases of these seizures, with the initial tonic phase involving widespread tensing up of muscles in your arms and legs and then the clonic phase involving convulsions.

What is the difference between a tonic-clonic seizure vs. other seizure types and epilepsy?

A tonic-clonic seizure has some similarities in name or symptom to other types of seizures. Those others include:

Atonic seizures. Also known as “drop attacks.” These seizures cause you to lose muscle control, making you drop to the ground. Fall injuries are common with these.
Tonic seizures. These are like a tonic-clonic seizure, but there’s no clonic phase. People may pass out during these and tighten up but don’t have convulsions.
Clonic seizures. These are also like a tonic-clonic seizure, but there’s no tonic phase. People may pass out and go straight to convulsions during these without their muscles tensing up.
Myoclonic seizures. These involve a quick muscle jerk or twitch that affects a group of muscles. When it affects your legs, it can cause you to fall. (NOTE: A myoclonic jerk, which is a sudden muscle twitch as you’re falling asleep, is normal. These aren’t a sign of seizures or epilepsy.)
Epilepsy: Epilepsy is a brain condition that puts you at risk of having spontaneous, unprovoked seizures. Healthcare providers diagnose it after you have at least two unprovoked seizures more than 24 hours apart at some point in your life, or a single unprovoked seizure and a high risk of having another within the next 10 years.

Who does it affect?

Everyone can have seizures, but some people can have them more easily. Seizures tend to happen most commonly in children and adults over 65.

How common is this condition?

Tonic-clonic seizures happen in about 25% of all people with seizures. Overall, 11% of people in the U.S. will have a seizure at some point in their life, and up to 3% of people will receive an epilepsy diagnosis during their lifetime. Seizures also make up about 1% of emergency room visits in the U.S.

How does this condition affect my body?

A seizure is a malfunction in how your brain cells (neurons) send and relay electrical signals. A seizure causes affected neurons to fire electrical signals uncontrollably to other nearby neurons, causing the malfunction to spread.

Tonic-clonic seizures are generalized seizures, which means this type of seizure affects both sides of your brain. These seizures make you pass out and affect muscles throughout your body, causing convulsions, shaking and other kinds of uncontrollable muscle movements.

Status epilepticus

Status epilepticus happens when a seizure lasts for more than five minutes, or another seizure starts before you recover from the first. Status epilepticus is a life-threatening medical emergency and can cause permanent brain damage or death.

Close to 98% of seizures last under five minutes. Anything that can cause seizures can also cause status epilepticus with tonic-clonic seizures (see the Causes and Symptoms section of our main Seizure article).

IMPORTANT NOTE: If you’re with someone who has a seizure that lasts more than five minutes or has a second seizure without enough time to recover from the first, you need to call 911 (or your local emergency services number) immediately. The longer that status epilepticus lasts, the harder it is for healthcare providers to stop the seizure causing it. Long-lasting status epilepticus is also more likely to cause brain damage or death.

Symptoms and Causes

What are the symptoms of a tonic-clonic (formerly known as grand mal) seizure?

Tonic-clonic seizures are usually what people think of when they think about seizures and epilepsy. The symptoms are usually more severe and easier to spot and happen in the following phases:

Tonic (usually 10 seconds – 30 seconds): During this phase, you pass out and muscles throughout your body go rigid (especially your arms and legs), making it look like you’re arching your back and lifting your belly upward. Your breathing muscles may force the air out of your lungs, causing you to cry out. Injuries are common if you fall or clench your teeth and bite your tongue.
Clonic (usually 30 seconds – 60 seconds, but sometimes longer): This phase involves convulsions, which are full-body spasms or shaking. You might also froth at your mouth. This phase usually winds down, with convulsions getting weaker and slower before stopping. As this phase ends, you might lose control of your bladder and bowels, causing you to urinate (pee) or defecate (poop).
Post-seizure recovery (up to 30 minutes): After a seizure, most people wake up and return to how they felt before the seizure. It’s common for you to feel confused, have a headache or feel muscle aches. In serious cases, you might take even longer to wake up, especially if you had status epilepticus.

Focal seizures and auras

Many people often experience a period before a seizure where they feel or know it’s going to happen. That lead-up time before the seizure, known as prodrome (rhymes with “dome”), can sometimes include what’s known as an “aura.” An aura happens when seizure activity starts to affect certain parts of your brain.

Generalized seizures, including tonic-clonic seizures, don’t have auras on their own. However, focal seizures — which affect only one side of your brain — can turn into generalized tonic-clonic seizures if the seizure spreads to the other half of your brain. That means an aura before a focal seizure can act as a warning that a tonic-clonic seizure could happen next.

Auras can involve the following symptoms:

Sensory symptoms: If an aura affects areas of your brain connected to your senses, those neurons can mistakenly act as if they’re getting real input. That can cause symptoms such as seeing bright lights or distortions in how objects appear, hearing unexpected sounds, sudden unexpected tastes of smells, strange feelings on your skin and more.
Emotional changes: Auras cause some people to feel negative emotions like fear or anxiety or positive emotions like joy or excitement. Other people may feel déjá vu (“day-zha voo,” the French term for when a new experience somehow feels familiar) or jamais vu (“zha-may voo,” the French term for when a familiar experience somehow feels new).
Autonomic symptoms: Auras can affect systems in your body that your brain runs automatically. Some examples include sweating, making too much saliva or drooling, your skin going pale or turning red, and more. Auras commonly cause “gastric uprising,” a rising feeling in your belly.

What causes tonic-clonic seizures?

Conditions and circumstances that can lead to tonic-clonic seizures include:

Aneurysms.
Irregular heart rhythms (arrhythmias), especially when they disrupt blood flow to your brain.
Brain tumors (including cancer).
Cerebral hypoxia (lack of oxygen).
Concussion and traumatic brain injury.
Degenerative brain diseases like Alzheimer’s disease or frontotemporal dementia.
Drugs and alcohol (this includes prescription medications, recreational drugs and even caffeine).
Drug or alcohol withdrawal.
Eclampsia (a condition where high blood pressure can cause seizures in people who are pregnant).
Electrolyte problems, especially low sodium (hyponatremia), calcium or magnesium.
Fevers, especially high ones (see our article on febrile seizures, including what to do for a loved one or child who has one) in children.
Flashing or flickering lights, especially in television shows, movies, video games and more.
Genetic disorders (conditions you have at birth that you inherited from one or both parents).
Hormone-related changes (for example, catamenial epilepsy can affect people with a menstrual cycle, making seizures happen more often at certain points in the cycle).
Infections (especially encephalitis or meningitis; infections can happen because of viruses, bacteria, parasites or fungi).
Inflammation from autoimmune conditions (where your immune system attacks your brain).
Insomnia and other problems that keep you from sleeping enough.
Metabolic problems, especially high blood sugar (hyperglycemia) or low blood sugar (hypoglycemia).
Mental health problems (known as psychogenic seizures) like conversion disorder.
Problems with your brain structure (especially ones that happen because of a problem with how your brain developed in the uterus).
Sepsis (a life-threatening overreaction of your immune system that happens because of an infection spreading throughout your body).
Strokes or transient ischemic attacks (TIAs).
Toxins and poisons (such as carbon monoxide poisoning or heavy metal poisoning).

Provoked vs. unprovoked seizures

When diagnosing a seizure, healthcare providers will also try to determine if a seizure had a provoked or unprovoked cause.

Provoked seizures: These happen as a symptom of other conditions or under specific circumstances (high fevers, low blood sugar, prescription or recreational drugs, alcohol or drug withdrawal).
Unprovoked seizures: These seizures aren’t symptoms of a current, short-term medical condition or circumstance. This also includes seizures that happen more than seven days after a specific cause (like a head injury or stroke).

Are tonic-clonic seizures contagious?

No, tonic-clonic seizures aren’t contagious. However, you can spread conditions like infections that cause them (but none of these will definitely cause a seizure). Also, some conditions that cause seizures are genetic (you can inherit them from your parents, or your children can inherit them from you).

Diagnosis and Tests

How are tonic-clonic seizures diagnosed?

Your healthcare provider, usually a neurologist, can often diagnose a tonic-clonic seizure based on the symptoms. Because you pass out during a tonic-clonic seizure, you might only recall how you felt before and after the seizure. In those cases, your healthcare provider may ask someone who was with you to describe what happened.

If you see someone having a seizure, especially one involving a lot of muscle tension, convulsions or shaking and thrashing, a healthcare provider might ask you to describe what you saw. What you describe to them can be very helpful and make the diagnosing process much easier.

What tests will be done to diagnose tonic-clonic seizures?

Several possible tests can help diagnose (or rule out) tonic-clonic seizures. Some of the most likely tests include:

Electroencephalogram (EEG).
Blood tests (these look for metabolic and blood chemistry imbalances, immune system problems, toxins and poisons and more).
Computerized tomography (CT) scan.
Magnetic resonance imaging (MRI).
Spinal tap (lumbar puncture).

While diagnosing epilepsy, healthcare providers will look for a focal point, a part of your brain where your seizures usually or always start. Finding a focal point can make a big difference in the treatments you receive.

Injuries are common with tonic-clonic seizures, either from passing out, clenching your jaw or if you collide with any nearby objects during the seizure. If healthcare providers suspect other injuries or complications from these seizures, they might want to run tests other than those listed above. Your healthcare provider is the best person to tell you (or someone who can make medical decisions for you) what kind of tests they recommend for your particular case and why.

Management and Treatment

How are tonic-clonic seizures treated, and is there a cure?

Tonic-clonic seizures usually stop on their own, and there’s no reason to treat them directly while they’re happening. An exception is if you have status epilepticus, which is when a seizure lasts longer than 5 minutes, or you don’t recover fully from a seizure before having another.

The possible treatments related to seizures also depend on what caused the seizure in the first place. If you had a provoked seizure, treating or curing the underlying condition that caused the seizure should stop the seizures from happening. If the underlying cause isn’t curable or treatable, healthcare providers will try to reduce how often your seizures happen or how severe they are.

Healthcare providers also typically recommend against treating first-time unprovoked seizures. That’s because there’s no certainty that another will happen, which would make treatment unnecessary.

Healthcare providers can use your medical history and tests like EEG, CT scan or MRI scan to determine if you have a higher risk of having another seizure.

What medications or treatments are used?

The treatments for all types of seizures vary widely, which is also true for epilepsy that specifically causes tonic-clonic seizures. For some people, one medication is enough to treat their seizures. For others, a combination of medications and treatments is necessary.

Possible treatments for tonic-clonic seizures due to epilepsy include:

Medications. Intravenous (IV) medications can treat a seizure while it’s happening; though, this usually only happens during status epilepticus. You can also take medications every day in pill form to help prevent seizures or decrease how often they happen. Medications are typically the first line of treatment for seizures that happen because of epilepsy.
Epilepsy surgery. When medications don’t work, surgery can sometimes stop seizures by removing or disconnecting the focal point from the rest of your brain. Healthcare providers typically recommend evaluating you for epilepsy surgery if your seizures continue even after you try two anti-seizure medications at recommended doses.
Diet changes. Low- or no-carb (ketogenic) diets can sometimes prevent seizures entirely or reduce how often you have them. Though these diets are tricky to follow, they can help when medications don’t work or cause severe side effects. They can also help if you need to or want to avoid surgery.
Brain stimulation. This treatment uses a device implanted into your brain that delivers a mild electrical current. This current interferes with and tries to stop the electrical activity of a seizure. Two forms of brain stimulation, deep brain stimulation and responsive neurostimulation, are currently available.
Vagal nerve stimulation. Your 10th cranial nerve, the vagal nerve, connects directly to your brain. Electrical stimulation on the left side of this nerve can help reduce how often your seizures happen.

What are the treatments’ possible complications or side effects?

The possible side effects and complications of the stated treatments depend on the treatments themselves, your health history and conditions, and the type of epilepsy you have. Your healthcare provider can tell you more about the possible side effects or complications. They can also tell you any possible concerns to watch for and how you can minimize how any of these affect you.

How to take care of myself or manage my symptoms?

You shouldn’t try to self-diagnose or treat any kind of seizure. That’s because seizures are often a sign of very serious medical conditions that affect your brain. Tonic-clonic seizures also cause you to pass out, which means you’re not aware of what happens during the seizure itself, so there’s no way of knowing what happened to you during the time you were unconscious.

If you or a loved one have a first-time seizure, seeing a healthcare provider is extremely important. A qualified provider can look for any signs of a seizure, as well as conditions that could cause them.

What should I do if someone I’m with has a seizure?

If you’re with someone who’s having a seizure, there are several things you can do as part of seizure first aid. Some dos and don’ts include:

Dos

Make sure they can breathe. Loosen any clothing around the person’s neck to make sure they’re breathing.
Move dangerous objects away from them. This includes breakable objects or items that might fall and hurt them. If they wear glasses, carefully take the glasses off and move them out of reach.
Put them in the rescue position. Turn the person on their side. This position helps protect a person’s ability to breathe and keeps them from inhaling any fluid like saliva or vomit.
Try to time the seizure as best you can. Telling a healthcare provider how long the seizure lasted can be critical information. It can also help you know if you need to call for emergency medical help.
Stay with them as they come out of the seizure and recover. People who have a seizure often feel confused or afraid as they wake up and return to normal. Help reassure and comfort them.
Make sure they’re OK once they wake up. If they have any injuries after the seizure, check if they need medical care. If the person hit their head or there’s a risk of an injury to the head, neck or back, the safest thing to do is to get medical care and make sure there aren’t any serious injuries that you can’t see.
Call for help if the person has status epilepticus. Call 911 (or your local emergency services number) if the seizure lasts more than five minutes or the person has another seizure before recovering from the first. Status epilepticus is a life-threatening medical emergency.

Don’ts

Don’t restrain them. You could hurt the person or get hurt yourself.
Don’t put anything in their mouth. There are many myths about seizures and epilepsy. One myth is that putting something in a person’s mouth like a belt or spoon can keep them from swallowing or biting their tongue. Don’t do this. You shouldn’t put anything into the mouth of someone having a seizure. You could hurt them or get hurt yourself.
Don’t panic. Stay calm. If others around you are panicking, reassure them as best you can.

How soon after treatment will I feel better?

The recovery time depends on the specific treatment(s) and the condition that caused your seizure. Your healthcare provider can provide more information about what you can and should expect, including how long you’ll need to recover and when you should start feeling better.

Prevention

How can I reduce my risk, and are seizures preventable?

Seizures can happen to anyone under the right circumstances, so seizures aren’t completely preventable. However, some people can have seizures more easily, so you can take certain proactive steps to lower your risk of them happening.

The best things you can do to reduce your risk of having a seizure include:

Eat a balanced diet and maintain a healthy weight. Managing your diet can help you avoid circulatory diseases and conditions such as stroke, as well as electrolyte problems (too much or too little sodium, for example).
Don’t ignore infections. Treating infections reduces the risk of seizures because of an infection or with a high fever related to an infection.
Wear safety equipment. Safety equipment, such as a helmet or safety belts or harnesses, can help you avoid seizures related to a head injury.
Don’t abuse alcohol, prescription or recreational drugs. Abusing and withdrawing from these can both lead to seizures. If you have a dependence on alcohol or any kind of drug, your primary care provider can help you find resources and specialized care to help you overcome alcohol or substance abuse.
Manage your health conditions. Chronic health conditions can often cause seizures directly or contribute to other seizure-related conditions. An example of this is managing your blood sugar if you have Type 1 diabetes or Type 2 diabetes.
Avoid possible seizure triggers. People with a history of seizures from flashing lights or other known sources should use caution and avoid similar triggers whenever possible.

Outlook / Prognosis

What can I expect if I have one or more tonic-clonic seizures?

About half of the people who have an unprovoked seizure will have another, and about 75% of those who have a second seizure will have more. That’s why healthcare providers often diagnose epilepsy and recommend starting anti-epilepsy medications after a second unprovoked seizure.

For those who start medication, it might take trying more than one medication or combination of medications. If medications don’t help, there are still other treatments that could make your seizures happen less often or make them less severe.

How long will I have this condition?

Stopping provoked seizures depends on whether or not the underlying condition or problem causing them is treatable or curable. Many people who have provoked seizures don’t have them as long as the underlying problem is gone and doesn’t return.

Epilepsy is a life-long condition because it’s not curable. However, it’s possible to treat the underlying cause of the seizures in some cases. When this works, your case is “in remission” as long as you’re seizure-free.

What’s the outlook for tonic-clonic seizures?

With provoked tonic-clonic seizures, the prognosis depends on the underlying condition. The prognosis is usually better if the condition is treatable and you quickly get treatment. Your healthcare provider is the best person to tell you the prognosis for your case and what you can do to help yourself. They can tailor that information to your needs and circumstances and direct you to other providers and resources for additional help.

Provoked seizures that happen with permanent or severe conditions, such as cancer or permanent brain damage, are sometimes treatable but usually have a lower chance of a good outcome because of why they’re happening. A positive outlook is also less likely for seizures due to genetic and congenital conditions (which you’re born with).

The outlook for unprovoked seizures depends on several factors. These include the underlying condition, the severity of your seizures, how often you have them and whether or not treatments help.

Sudden unexpected death in epilepsy

Sudden unexpected death in epilepsy (SUDEP) is a rare condition that can affect anyone with epilepsy but is less likely with treatment. The risk of SUDEP is 1 in 150 for people with untreated epilepsy, while the risk for those with treated epilepsy is 1 in 1,000.

Experts don’t fully understand why SUDEP happens yet. For now, the best available explanation is that it happens due to heart or breathing problems that are possible with seizures.

Living With

How do I take care of myself?

If you’ve experienced a single tonic-clonic seizure in the past, it’s a good idea to know what to do if you have another. You should also see your healthcare provider as soon as possible if you have another seizure or develop a condition that could cause one.

If your healthcare provider diagnoses you with epilepsy, there are several things you can do to help yourself and manage this condition.

Take your medication as prescribed. It’s important that you keep taking your medications even if you feel better. The only time you should stop your medications is if you first talk about it with your healthcare provider.
Talk to your healthcare provider about alternatives. Talk to your healthcare provider if you want to taper off or switch medications. They can guide you on how to do this safely and what alternatives you can try.
See your healthcare provider as recommended. These visits are very important to help manage and monitor your condition and to make sure your medications and treatments are working.
Don’t ignore or avoid symptoms. Early diagnosis and treatment can make a huge difference with seizures and epilepsy.

When should I go to the ER?

You should go to the emergency room if you have any event that makes you pass out, and you don’t know what caused it. While many people have others around to see them have a first-time seizure, many don’t. If you’re alone and you have what you think is a first-time seizure, you should see your healthcare provider right away.

Calling an ambulance after a seizure is often unnecessary if the person knows they have epilepsy. However, they may need medical attention if they have injuries from the seizure.

When should I call for help?

If you’re with someone who has a seizure, you should keep in mind the following:

Call for help if this is their first seizure. A healthcare provider should examine anyone after a suspected or confirmed first-time seizure. That’s because seizures are often a sign of more serious health problems.
Call for help if the person has status epilepticus. Call 911 (or your local emergency services number) if the seizure lasts more than five minutes, or if the person has another seizure before they recover from the first. Status epilepticus is a life-threatening medical emergency. You should also call for emergency help if they don’t start recovering or are unresponsive for more than 10 to 15 minutes after the convulsions stop. That may be a sign of a seizure continuing in their brain even though their body isn’t shaking any longer.

Is it safe to become pregnant if I have epilepsy and take medication?

People with epilepsy can often still have children. However, many anti-epilepsy medications aren’t safe to take during pregnancy because many disrupt how a baby develops in your uterus.

Fortunately, other medications can serve as temporary alternatives during part or all of a pregnancy. Your healthcare provider is the best person to talk to about this and can either guide you directly or refer you to a specialist who can.

A note from Cleveland Clinic

Tonic-clonic seizures are the most visible — and often most feared — type of seizure. While these seizures are often scary for the people who have or witness them, most of these only last a few minutes. While they can happen for many reasons, these seizures often go away on their own, especially with treatment of the underlying condition causing them. There are also many different ways of treating these seizures when they happen with epilepsy. With effective treatment, many people with these seizures — even those with epilepsy — can live fulfilling, happy and rewarding lives.

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Tonic-Clonic (Grand Mal) Seizure