U.S. flag

An official website of the United States government

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

InformedHealth.org [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006-.

Cover of InformedHealth.org

InformedHealth.org [Internet].

Show details

Overview: Epilepsy

Last Update: May 4, 2023; Next update: 2026.


In epilepsy, the brain or some parts of the brain are overactive and send too many signals. This results in seizures, also referred to as epileptic fits. Seizures sometimes only cause a few muscles to twitch – but they may also cause your whole body to convulse (shake uncontrollably) and result in loss of consciousness.

Epilepsy can arise at any age. Some people already have their first seizure in childhood, and others have their first seizure in older age. There are usually no physical symptoms in between seizures. Many people worry about having another seizure, though.

Medication can help to prevent seizures and maintain a good quality of life. Unfortunately, it doesn't always help: About 3 out of 10 people still have regular seizures. This makes it particularly difficult for them to live with epilepsy.

At a glance

  • Epileptic seizures ("fits") can make individual muscles or your whole body jerk and shake. Some people also lose consciousness.
  • These seizures don't lead to any long-term damage.
  • It is only considered to be epilepsy if the seizures recur.
  • Medication can help to prevent seizures.
  • The most important thing that helpers can do during an epileptic seizure is stay calm and prevent injury.
  • Call the emergency services (112 in Germany and most European countries, 911 in the U.S.) if the seizure lasts longer than five minutes or if several seizures occur within a short space of time.


Epileptic seizures can vary greatly from person to person. Some only last a few seconds and even go unnoticed, some only affect one arm or one leg, whereas others affect the whole body. Sometimes people become unconscious, sometimes they are just mentally absent for a short while, and sometimes they remain fully conscious.

Epileptic seizures don't usually last very long. If a seizure lasts longer than five minutes, it is referred to as "status epilepticus." This is a medical emergency requiring immediate treatment with medication. People may also have several seizures within a short space of time.

There are two main categories of epileptic seizures:

  • Generalized seizures
  • Partial (focal) seizures

Generalized seizures

Generalized seizures affect the whole brain. They aren't necessarily worse than seizures that affect individual parts of the brain (partial seizures). But generalized seizures are more likely to lead to loss of consciousness and make your whole body convulse.

There are different types of generalized seizures:

  • Tonic seizures: Your arms and legs become rigid and stiff. This kind of seizure usually passes quite quickly and doesn't always affect your state of consciousness.
  • Atonic seizures ("drop attacks"): Here the muscles in one part of your body suddenly become limp. As a result, your chin might drop down towards your chest, or your legs might give way, for instance. You may also briefly become unconscious and fall.
  • Clonic seizures: Large muscle groups – for instance in the arms or legs – jerk in a slow rhythm. This is usually accompanied by loss of consciousness.
  • Myoclonic seizures: Individual muscle groups twitch rapidly. Your state of consciousness is usually not affected.
  • Tonic-clonic seizures (sometimes called "grand mal seizures"): Your whole body convulses and twitches, and you become unconscious.
  • Absence seizures (sometimes called "petit mal seizures"): In this mild type of seizure, people suddenly lose awareness (appear to "zone out") for a brief moment.

Partial (focal) seizures

Partial seizures arise in just one part of the brain. The symptoms will depend on what that part of the brain does, and may include things like twitching of the arm (motor disturbances), abnormal sensations (sensory disturbances) or changes in vision (visual disturbances).

When people have partial seizures they may experience abnormal sensations, lose awareness, or hear, see or smell things differently. They may also feel dizzy, feel anxious or hallucinate. This is known as an aura. Some people smack their lips, grimace, stammer, walk around aimlessly or fiddle with things. Partial seizures may be accompanied by twitching or convulsions. Sometimes partial seizures affect your awareness or ability to concentrate.

Partial seizures may spread across the whole brain, resulting in a generalized seizure.

People with epilepsy usually don't have any physical symptoms in between seizures.

Causes and risk factors

The brain is made up of billions of nerve cells (neurons). Different areas of the brain are responsible for different things, including movement, speech, perception and feelings. The nerve cells communicate with each other using electrical and chemical signals. During an epileptic seizure, the interactions between nerve cells temporarily go haywire.

As a result, certain areas of the brain or all areas of the brain become overly active and fire off too many signals. The resulting "storm in the brain" has noticeable effects, such as convulsions, in the rest of the body.

Epilepsy can be caused by a wide variety of things, including injuries, inflammations of the brain or the lining of the brain, strokes or tumors. If there is a known cause for someone's epilepsy, it is referred to as "symptomatic epilepsy." But it is often not possible to find a clear cause.

Sometimes several people in different generations of a family have epilepsy. This is a sign that it may be genetically inherited.

Things like strobe lights in night clubs can trigger seizures in some people. Certain conditions might also sometimes cause seizures. Examples include not getting enough sleep, a lack of oxygen, poisoning, alcohol or – particularly in children – a high fever. These kinds of factors can even cause a seizure in someone who doesn't have epilepsy. It is then known as a provoked seizure. Children who are prone to febrile seizures, for instance, only rarely have epilepsy as well.


Doctors only consider it to be epilepsy if someone has had a number of seizures for no apparent reason. That happens in just under 1 out of 100 people. Including provoked seizures, it's estimated that about 10 out of 100 people will have at least one seizure at some point in their life.

Epilepsy can arise at any age. Many people who have epilepsy already develop it in childhood. It is a little less likely to develop in middle age, between the ages of 40 and 59. The likelihood then increases again in people aged 60 and over.


Many people only ever have one seizure in their life, or only have epilepsy for a few months or years. Others have it all their lives. About half of all people who have one seizure will have another one. People who have had a second seizure are even more likely to have further seizures: About 7 out of 10 of them have another seizure within a few years.

But these are only averages. The individual’s risk of having another seizure will greatly depend on the exact cause. For instance, some people have seizures for no known reason or because they have a genetic predisposition (it runs in their family). Compared to them, people who have had seizures with a known cause (such as a brain disease) are twice as likely to have further seizures.

Some people take medication and don't have seizures for years – even after they stop taking the medication. Others only remain seizure-free when they are on medication. About 3 out of 10 people with epilepsy have regular seizures despite having various kinds of treatment.


It can take a while to recover from more severe epileptic seizures. Some people are exhausted for a few hours afterwards, and sleep a lot. They may also feel down for a bit or have temporary problems with forgetfulness, speech, or paralysis. Other people feel normal again after a few minutes and can return to work or school activities.

Epileptic seizures may lead to injury. This is particularly likely if people have generalized seizures, where their whole body convulses (shakes uncontrollably). They could fall, hurt themselves or bite their tongue.

The fear of having another seizure can be very distressing, especially if they occur frequently. Epilepsy can also increase the likelihood of developing depression.

Epileptic seizures don’t cause lasting damage to the brain or result in mental disability. Having frequent and severe seizures over many years can make you more forgetful and less able to concentrate, though.

Whether epilepsy affects your life expectancy will very much depend on what is causing it. People whose epilepsy is caused by another medical condition generally tend to have a shorter life expectancy, but that's often due to the underlying condition, not the epilepsy. People whose epilepsy is caused by genetic factors have a similar life expectancy to people without epilepsy.

Epilepsy can itself lead to death in the following situations:

  • If someone has an accident because of a seizure and it results in a life-threatening injury.
  • If a severe, long-lasting seizure (status epilepticus) prevents the brain from getting enough oxygen, and that leads to heart and lung failure.

Sudden, unexpected death in epilepsy (abbreviated as SUDEP) is extremely rare.


Epilepsy is usually diagnosed if

  • at least two seizures have occurred,
  • there was a period of at least 24 hours between the seizures, and
  • there is nothing to suggest that the seizures were caused by certain factors (provoked seizures).

Epilepsy can also be diagnosed if the risk of having a second seizure is considerably higher after the first seizure.

There are special (rarer) types of epilepsy too, known as epilepsy syndromes. These include absence epilepsy and infantile spasms (West syndrome), which can occur in children.

Your medical history is important for making a diagnosis: For instance, when and under what circumstances did the seizure occur? What happened during the seizure? People who have seizures often can’t remember much about what happened themselves. Then it makes sense to take someone along who saw the seizure and can describe exactly what happened.

Physical and neurological examinations are done, and a blood sample is taken.

An electroencephalogram (EEG) is also usually done to measure the electrical activity of your brain. Certain EEG patterns indicate that you are more likely to have seizures. But an EEG alone isn’t enough to diagnose epilepsy.

An MRI (magnetic resonance imaging) scan is usually done too. This helps to find out whether there are changes in the brain that could be causing the seizures.

In rare cases the cerebrospinal fluid is tested – typically if doctors think that you might have an inflammation in your brain or in the membranes surrounding the brain and spinal cord (meningitis). The fluid is taken from the lumbar (lower back) region of the spine, using a needle. This procedure is known as a lumbar puncture or spinal tap.


The most suitable kind of treatment for a specific person will depend on the type of epilepsy they have and the course of their disease so far. Epilepsy is usually treated with medication known as anti-epileptic drugs (AEDs). Various kinds of medications – from different groups of drugs – can be used as AEDs. If a certain medication doesn’t work at a low dose, the dose can be increased. If that doesn’t work, a medication from a different group of drugs can be tried out or several medications can be used together.

Seizures are often one-off events, so you can usually wait before having any treatment. People typically only start treatment if they have a second seizure. But if you have a higher risk of further seizures, for example if you have a brain disease, then it may be a good idea to already start with treatment after the first seizure. It is important to discuss your personal situation with your doctor.

People who decide to take medication usually take it for several years. If they don't have any seizures during that time, some people can stop taking the medication and see what happens. Others have to take medication for the rest of their lives.

Anti-epileptic drugs can have side effects like tiredness or dizziness. There are also sometimes specific risks, for example ones affecting an unborn baby during pregnancy. Then it's especially important to discuss the options in detail with your doctor.

If seizures can’t be prevented with medication, other options may be considered. These include the following:

  • Surgery: If someone has partial seizures and it's clear which part of the brain is triggering them, that part of the brain can be surgically removed. But that's not always possible.
  • Vagus nerve stimulation: In this procedure, a device that produces electrical signals is implanted in your chest area. It is connected to the vagus nerve in the neck by wires and is meant to prevent the nerve cells from being too active. The vagus nerve is an important part of the vegetative nervous system and is involved in regulating the body's internal organs. So far there are only a few good-quality studies on the benefits of this treatment. As a result, statutory health insurers in Germany only cover the costs of vagus nerve stimulation in very specific cases, under special circumstances.

The treatment is overseen by a neurologist. Children are treated by child neurologists (pediatric neurologists). One part of the examination and treatment is usually done in a hospital. There are outpatient facilities and clinics that specialize in treatments for people with epilepsy (e.g. epilepsy centers, epilepsy outpatient hospital departments, and specialized doctors’ practices). These are particularly suitable if you have a specific problem, if the diagnosis is not clear, or if you keep on having seizures despite treatment.

The most important thing that helpers can do during an epileptic seizure is stay calm and prevent injury. If the seizure lasts longer than five minutes or if several seizures occur within a short space of time, the emergency services should be informed (e.g. by calling 112 in Germany and most European countries, or 911 in the U.S.). People who have a severe epileptic seizure sometimes have to stay in hospital for a bit.

It may be helpful to have psychological treatment too. This can help you to cope with the effects of epilepsy and improve your quality of life. It is not yet clear from scientific research whether this can also lower the number of seizures.

Further information

When dealing with epilepsy, there are many questions that can only be answered on a very individual level. The following list of questions might help you to prepare for your doctor’s appointment:

  • What exactly is the diagnosis?
  • What are the medication options? What advantages and disadvantages do they have?
  • What are the other treatment options? What advantages and disadvantages do they have?
  • What triggers seizures and how can I lower my risk of having them? Would changing my lifestyle help?
  • What precautionary measures can I take to increase my safety during seizures?
  • What do I have to watch out for at home and at work, for example when driving a car?
  • Will my epilepsy affect my ability to have children?
  • What consequences does it have for my health insurance?
  • Where can I find further help and support?

Teenage girls and women with epilepsy might need professional advice about specific issues such as contraception, pregnancy and breastfeeding. Older people and people with a mental disability also often have particular challenges that require specialist advice.

Support is available from doctors, support groups and information centers.


© IQWiG (Institute for Quality and Efficiency in Health Care)
Bookshelf ID: NBK343313


Informed Health Links

Related information

  • PMC
    PubMed Central citations
  • PubMed
    Links to PubMed

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...