What is a seizure?
A seizure is a medical condition where you have a temporary, uncontrolled surge of electrical activity in your brain. When that happens, the affected brain cells uncontrollably fire signals to others around them. This out-of-control electrical activity overloads the affected areas of your brain.
That overload can cause a wide range of symptoms or effects. The possible symptoms include abnormal sensations, passing out and uncontrolled muscle movements. Treatment options, depending on seizure type, include medications, surgeries and special diet changes.
The term seizure comes from the ancient belief in multiple cultures that seizures were a sign of possession by an evil spirit or demon. However, modern medicine has uncovered the truth: Everyone can have seizures, and some people can have them more easily than others.
What is the difference between seizures and epilepsy?
Understanding the difference between seizures and epilepsy starts with knowing seizures fall into two main categories depending on why they happen.
- Provoked seizures: These happen because of other conditions or circumstances (high fevers, alcohol or drug withdrawal, low blood sugar). Provoked seizures make up about 25% to 30% of all seizures.
- Unprovoked seizures: These aren't symptoms of a current medical condition or circumstance and occur when a person’s brain can more easily produce spontaneous seizures. This also includes seizures that happen more than seven days after a specific cause (like a head injury or stroke).
Epilepsy is a brain condition that puts you at risk of having spontaneous, unprovoked seizures. Healthcare providers diagnose it when you have at least two unprovoked seizures, or you have a single unprovoked seizure and have a high risk of having at least one more in the next 10 years. Having a single unprovoked seizure increases the odds of having another. Provoked seizures aren’t enough for a provider to diagnose you with epilepsy.
Who does it affect?
Everyone can have seizures, but some people have medical conditions that make them happen more easily. Seizures are also more likely at certain ages. Children are more likely to have seizures and epilepsy, but many grow out of the condition. The risk of having a seizure or developing epilepsy also starts rising at age 50 because of conditions like stroke.
How common are seizures?
Seizures are uncommon but are still well-known by most people. Up to 11% of people in the U.S. will have at least one seizure during their life.
Epilepsy is much less common. Between 1% and 3% of people in the U.S. will develop epilepsy during their lifetime.
How do seizures affect my body?
Your brain contains billions of cells known as neurons. These cells transmit and relay chemical and electrical signals to each other. A single neuron in your brain connects to thousands more, forming communicating networks. Those networks are how different parts of your brain work together so you can do things like solve problems, store memories and move around.
Seizures happen when a malfunction causes neurons to fire electrical signals uncontrollably. That causes a domino effect, meaning more and more neurons go haywire. The more malfunctioning neurons, the greater the effect of the seizure. If these malfunctions happen often enough, it can affect how your brain cells work and make it easier for seizures to happen.
If they keep happening or seizures last too long, these electrical malfunctions will damage and destroy your brain cells. When this happens to enough neurons in a part of your brain, the result could be permanent brain damage. Seizures can also cause severe changes in your blood chemistry as your body tries to manage the physical effects of convulsions. The chemical changes in your blood can cause permanent brain damage if they last too long (see the “Status epilepticus” heading below).
How the spread of a seizure affects your body
Seizure types depend partly on where they happen in your brain. A healthcare provider can determine where they happened based on your symptoms.
Seizure location tends to happen in two main ways:
- Generalized seizures. These are seizures that happen in both sides (hemispheres) of your brain side. These seizures tend to cause more severe effects and symptoms.
- Focal seizures: Also known as partial seizures, these happen in only one hemisphere. That means symptoms only happen in a specific part or on one side of your body. But focal seizures can sometimes spread and become generalized seizures.
Status epilepticus happens when a seizure lasts for more than five minutes, or you have more than one seizure without enough time between to recover. Status epilepticus is a life-threatening medical emergency because it can cause brain damage or even death.
Other problems and effects
Seizures often involve passing out. When that happens, there’s a risk of injuries from falling or from what you’re doing at the time (like driving or operating machinery).
Symptoms and Causes
Are there any warning signs before a seizure?
Many people experience a period where they can feel that a seizure is going to happen. That lead-up time, known as prodrome (rhymes with “dome”), can sometimes include what’s known as an “aura.” An aura is actually a symptom of a focal seizure, which only affects one side of your brain.
When focal seizures don’t spread, an aura is the only effect of the seizure. When focal seizures do spread throughout your brain, an aura is more like a warning sign that a more severe seizure is about to happen.
Auras can also take many different forms. These include:
- Sensory symptoms. If an aura affects areas of your brain connected to your senses, those neurons can mistakenly act they’re getting real input. That can cause symptoms like seeing bright lights or distortions in how objects appear, hearing unexpected sounds, sudden unexpected tastes of smells and strange feelings on your skin.
- 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 body systems that your brain runs automatically. Some examples include sweating, making too much saliva or drooling and your skin going pale or turning red. A common aura is “gastric uprising," a rising feeling in your belly.
What are the symptoms of a seizure?
Different types of seizures have different kinds of symptoms, and describing the symptoms to a healthcare provider can help them diagnose and treat the kind of seizures you have. The two main types of seizures are focal and generalized.
The main types of generalized seizures are:
- Tonic-clonic seizures.
- Absence seizures.
Formerly known as “grand mal” seizures (French for “great illness”), tonic-clonic seizures are usually the most recognizable. They happen in the following phases:
- Tonic (usually 10 - 30 seconds): During this phase, you pass out as all your muscles tense up. Falls and injuries are common.
- Clonic (usually 30 – 60 seconds, but sometimes longer): This phase involves uncontrolled convulsions (muscle movements).
- Post-seizure recovery (up to 30 minutes): During this phase, you wake up and return to how you were before the seizure. Confusion and muscle aches are common.
Formerly known as “petit mal” (French for “little illness”) seizures, these are most common in children. Absence seizures often look like daydreaming, “spacing out” or staring off into the distance (a “thousand-yard stare”). These seizures end quickly with no recovery period needed.
Absence seizures are short-lived but you can have dozens or even hundreds of times in a day. They’re easily confused for distraction or a sign of a learning disability.
Other types of generalized seizures
Generalized seizures can happen in other ways that have similarities to those above:
- Tonic seizures. Like a tonic-clonic seizure, but there’s no clonic phase. People pass out during these and tighten up but don't have convulsions.
- Clonic seizures. Also like a tonic-clonic seizure, but there’s no tonic phase. During these, people pass out and go straight to convulsions without their muscles tensing up.
- Atonic seizures. These are also known as “drop attacks.” During an atonic seizure, people lose control of muscles in their body, causing them to drop to the ground suddenly. There’s a high risk of injury from falling during these. This kind of seizure is most common with Lennox-Gastaut syndrome, a severe form of childhood epilepsy.
- Myoclonic seizures. These involve a quick jerk or twitch that affects one muscle or a group of connected muscles. When it affects your leg while standings, it can cause you to fall. (NOTE: While these are similar to a myoclonic jerk, which is a sudden muscle twitch as you’re falling asleep, they aren’t the same thing. Myoclonic jerks that happen as you fall asleep are normal and aren't a sign of seizures or epilepsy.)
Focal seizures affect a smaller area of your brain and stay in one hemisphere. These are also known as partial seizures, and auras — when they happen — come before these. Symptoms such as uncontrolled muscle movements may spread to different places on one side of your body, such as from one side of your face to the hand or foot on the same side.
Focal seizures include the following subtypes:
- Simple focal seizures. Sometimes known as simple partial seizures, you’re aware of these when they happen. With this kind of seizure, the aura is the seizure itself and not just a warning sign.
- Complex focal seizures. These are sometimes known as complex partial seizures. These disrupt your awareness of what’s happening to or around you.
Auras as warning signs
When a focal seizure spreads to the other side of your brain, it can turn into a generalized tonic-clonic seizure. If you’ve had a seizure in the past, or you know you have epilepsy, you should treat an aura like a warning sign. To protect yourself, you can do the following:
- Make yourself as safe as possible. Sit or lie down so you don’t fall and injure yourself. You should also stop what you're doing if it's something like driving or using heavy machinery or tools.
- Contact someone you trust to help you. Tell them where you are and how to find you.
- If you can’t contact someone you know, tell someone in your immediate surroundings who is in a position of responsibility or authority that you think you’re about to have a seizure. An example of this is telling a police officer or security guard, a teacher or a store employee.
What causes seizures?
Seizures can happen for many different reasons. These include:
- Brain tumors (including cancer).
- Cerebral hypoxia (lack of oxygen).
- Severe 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 pregnant people).
- Electrolyte problems, especially low sodium (hyponatremia), calcium or magnesium.
- Fevers, especially high ones (read more about febrile seizures, including what to do for a loved one or child who has one; they’re very common in children, and having these slightly increases the risk of having seizures or epilepsy later in life).
- Sensitivity to flashing or flickering light.
- 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).
- 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 you’ve had since birth).
- Strokes or transient ischemic attacks (TIAs).
- Toxins and poisons (such as carbon monoxide poisoning or heavy metal poisoning).
What are the kinds of seizures that affect children?
Children can have seizures for any of the above reasons. Fevers are one of the most common causes of childhood seizures. Other causes include:
- Juvenile myoclonic epilepsy. This condition usually starts in the mid-teenage years. The main symptom of this type of epilepsy is having one or more myoclonic seizures on both sides. These usually happen after waking up in the morning and are more likely with lack of sleep. Tonic-clonic and absence seizures are also possible.
- Lennox-Gastaut syndrome. This severe form of childhood epilepsy causes multiple types of seizures, and brain damage. Developmental delays are also common. It has a high injury risk because it commonly causes atonic seizures ("drop attacks").
Are seizures contagious?
No, seizures aren’t contagious. While you can spread conditions like infections that cause them, none will definitely cause a seizure. Also, some conditions that cause seizures are genetic (you can inherit them, or you can pass them to your children).
Diagnosis and Tests
How is a seizure diagnosed?
A healthcare provider, usually a neurologist, can diagnose a seizure based on symptoms you had and certain diagnostic tests. These tests may help confirm whether or not you had a seizure and — if you did — what might have caused it. Genetic tests can also help find inherited conditions that cause seizures (and sometimes even the most likely type of seizures you could have).
A key part of diagnosing seizures is finding if there’s a focal point — a specific area where your seizures start. Locating a focal point for the seizures can make a huge difference in treatment.
What tests will be done to diagnose this condition?
Possible tests with to help diagnose seizures include:
- Electroencephalogram (EEG).
- Blood tests (these look for things like metabolic and blood chemistry imbalances, immune system problems, toxins and poisons).
- Computerized tomography (CT) scan.
- Magnetic resonance imaging (MRI).
- Spinal tap (lumbar puncture).
Providers might also recommend tests if they suspect injuries, side effects or complications from a seizure. Your healthcare provider is the best person to tell you (or someone you choose to make medical decisions for you) what kind of tests they recommend and why.
Management and Treatment
How is a seizure treated, and is there a cure?
With provoked seizures, treating or curing the condition causing your seizures will usually make them stop. In cases where the underlying condition isn’t curable or treatable, healthcare providers may recommend medications to try to reduce how severe your seizures are and how often they happen medications.
Providers usually recommend against treating first-time unprovoked seizures. That’s because there’s no certainty that another will happen. An exception to that is if the person has a higher risk of having another seizure, or when a person has status epilepticus. Stopping status epilepticus is critical because it can lead to permanent brain damage or death. 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 seizures vary widely. That’s because the treatment for a provoked seizure depends almost entirely on the cause. The treatment for epilepsy-related seizures also depends on the type(s) of seizure you have, why they’re happening and which treatments work best.
Possible treatments for seizures due to epilepsy include one or more of the following:
- Medications. These are the first line of treatment for people with epilepsy. Different kinds of medications can stop seizures as they happen, and other kinds can prevent seizures or make them happen less frequently. Intravenous (IV) medications can treat a seizure while it's happening. You can also take daily medications to help prevent seizures or decrease how often they happen.
- Epilepsy surgery. When medications don’t work, surgery can sometimes stop seizures by removing or disconnecting the problem area from the rest of the brain. Healthcare providers will usually recommend an evaluation for epilepsy surgery if your seizures continue despite trying two anti-seizure medications at recommended doses.
- Diet changes. Low- or no-carb (ketogenic) diets can sometimes stop epileptic seizures entirely or reduce how often they happen. These diets can help when medications don't work. If surgery isn't possible, such diets can be an alternative for some people.
- Brain stimulation. This treatment uses a device implanted into your brain that delivers a mild electrical current. That 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. The 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.
Complications/side effects of treatment
The complications from seizure treatments vary widely, depending on the cause, type of seizure, type of treatment and more. Your healthcare provider is the best person to tell you what side effects or complications are most likely in your case. That's because they can give you specific information about your specific case.
How can I take care of myself or manage the symptoms of a first-time seizure?
You shouldn’t try to self-diagnose or treat a seizure. That’s because seizures are often a sign of very serious medical conditions that affect your brain. If you or a loved one have a first-time seizure, see a healthcare provider. Your healthcare provider can tell you what symptoms or effects to watch for that could mean you need medical care after a seizure.
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:
- 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 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 their 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. You should also call for emergency help if they don't start to recover 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.
- 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. Nearly 98% of seizures don't last more than five minutes.
How soon after treatment will I feel better?
The time to recover from treatment depends on the types of seizures you have and the treatments you receive. Your healthcare provider can tell you what you should expect, including how long you’ll need to recover and when you should start to feel better.
How can I reduce my risk?
Everyone is at risk for seizures, and they also happen unpredictably, so it’s not possible to completely prevent them. The best thing you can do is avoid possible causes to reduce the chances of having a seizure.
The best things you can do to reduce your risk of having a seizure include:
- Eat a balanced diet and maintain a weight that's healthy for you. Many conditions related to your circulatory and heart health, especially stroke, can damage areas of your brain. This is one of the main causes of seizures in people over age 65. This can also help avoid electrolyte problems (too much or too little sodium, for example).
- Don’t ignore infections. Eye and ear infections are especially important to treat. If these infections spread to your brain, they can cause seizures. Infections can also cause high fevers, which can lead to seizures.
- Wear safety equipment. Head injuries are a major cause of seizures. Using safety equipment (helmets, safety belts and restraints, etc.) whenever necessary can help you avoid an injury that leads to a seizure.
- Don’t misuse alcohol, prescription or recreational drugs. Misusing these can lead to seizures, and withdrawal from these substances can also lead to seizures if you're dependent on them.
- Manage your health conditions. Managing chronic conditions can help you avoid seizures, especially those that happen because of your blood sugar with either Type 1 diabetes or Type 2 diabetes.
- Avoid possible seizure triggers. People with a history of seizures from flashing lights should use caution and avoid similar triggers whenever possible.
Outlook / Prognosis
What can I expect if I have seizures?
Fewer than half of people who have a single unprovoked seizure will have another. If a second seizure happens, healthcare providers usually recommend starting anti-seizure medications.
Medications can help prevent seizures or reduce how often they happen. However, it sometimes takes trying multiple medications (or combinations of them) to find one that works best.
In some cases, people have “refractory epilepsy,” which resists medications. For people with refractory epilepsy, surgery, ketogenic diet or an implantable device are the next options to consider.
How long will I have this condition?
For provoked seizures, the risk of having another depends on what caused the first seizure and if that cause was treatable or curable. If it was treatable or curable, your risk of having another seizure is low (unless you have a repeat of the circumstances that caused the first seizure).
Many people who had an unprovoked seizure will never have another for the rest of their lives. For those who do have a second seizure, epilepsy is a life-long condition because it’s not curable. However, it’s possible for this condition to go into remission and for seizures to stop happening.
What’s the outlook for this condition?
For people who've had one or more seizures, the prognosis and outlook depend on several factors. These include:
- Did they find a cause for your seizure, and was it provoked or unprovoked?
- If they found a cause, was it treatable or curable?
- What type of seizure did you have?
- How severe was the seizure, and how long did it last?
- Was this your first seizure?
- If this wasn’t your first seizure, did a healthcare provider diagnose you with epilepsy?
- Did you receive treatment and, if yes, what did you receive?
In general, provoked seizures tend to have the best outlook if the underlying condition is treatable or curable. Provoked seizures with severe or recurring conditions are difficult to treat. It's also usually difficult to treat seizures and epilepsy that happen with congenital or inherited conditions.
The outlook for unprovoked seizures depends on the kinds of seizures, how often they happen, if medication helps them and more. In general, two-thirds of people with epilepsy can expect their seizures to be controlled for a year or longer after trying one to two well-chosen and well-dosed anti-seizure medications. Your healthcare provider is the best person to tell you the outlook and what you can do to help yourself. They can tailor that information to your specific case and direct you to other providers and resources for additional help.
Sudden unexpected death in epilepsy
There is a small risk of sudden unexpected death in epilepsy (SUDEP) for people with that condition. SUDEP happens for unknown reasons. Experts suspect it involves heart rhythm or breathing problems.
For people with controlled (treated) epilepsy, the death rate each year is about 1 person out of every 1,000. For people with uncontrolled (untreated) epilepsy, the death rate each year is about 1 out of every 150.
How do I take care of myself?
If you've had one seizure in the past, it's important to watch for signs of another. If you have a second seizure, seeing a healthcare provider as soon as possible is very important. Seizures cause changes in your brain that make it easier to have more seizures, so early diagnosis and treatment are key.
If a healthcare provider diagnoses you with epilepsy, you can help yourself by doing the following.
- Take your medication as prescribed. Taking your anti-epilepsy medications can make a huge difference in seizure frequency and severity. It's important that you keep taking your medications even if you feel better. You should never stop taking your medications without talking to your provider.
- Talk to your provider about alternatives. If you want to taper off or switch your medications, your healthcare provider determine if this is possible and guide you on how to do it safely.
- See your provider as recommended. Your healthcare provider will set up a schedule for you to see them. These visits are especially important to help with managing your conditions and finding the right medications or treatments.
- Don’t ignore or avoid symptoms. Seizures and epilepsy are more likely to respond and have a good outcome with early diagnosis and treatment.
- Avoid seizure triggers. If there are situations that increase your risk of seizures, such as flickering lights or sleep deprivation, it’s important to avoid those triggers. Doing so can help you better control your seizures.
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. If you're alone and have what you think is a first-time seizure, you should call or see your healthcare provider right away.
Calling an ambulance after a seizure is often unnecessary if a person has epilepsy. However, even if they know why they had a seizure, they may have injuries that need medical attention.
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. Seizures are often a sign of 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 to recover 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 have children. While many anti-epilepsy medications aren't considered safe during pregnancy, most people with epilepsy can still have healthy children by working with a healthcare provider. Your healthcare provider is the best person to talk to guide you on this or refer you to a specialist.
A note from Cleveland Clinic
Seizures are not an uncommon neurological condition. About 11% of people will have a seizure at some point in their life, but most will have only one, and it's often for a specific reason. That means the one seizure won’t ever be a problem again. People who have more than one seizure without a specific underlying reason have epilepsy. While epilepsy is often a frightening condition, there are ways to treat it. With treatment, many people with epilepsy can live happy, fulfilling lives.
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