Epilepsy is a condition that affects the brain and is defined by repeated seizures.

Epilepsy affects more than 600,000 people in the UK. Almost one in every 100 people has the condition.

Symptoms of epilepsy

The main symptoms of epilepsy are repeated seizures. There are different types of seizure, depending on which part of the brain it affects.

The cells in the brain, known as neurons, conduct electrical signals. They communicate with each other in the brain using chemical messengers. During a seizure, there are abnormal bursts of neurons firing off electrical impulses. This can cause the brain and body to behave strangely.

The severity of seizures can differ from person to person. Some people experience an odd feeling with no loss of awareness, or may have a "trance-like" state for a few seconds or minutes. Others lose consciousness and have convulsions (uncontrollable shaking of the body).

Some people might only have a single seizure. If they do not have a high risk of having further seizures, they would not be regarded as having epilepsy.

Types of seizures

People with epilepsy can experience any type of seizure, although most people have a consistent pattern of symptoms.

Seizures can occur when you're awake or asleep.

The type of seizure depends on how much of the brain it affects. There are:

  • focal (or partial) seizures – where only a small part of the brain is affected
  • generalised seizures – where most or all of the brain is affected

Some seizures do not fit into these categories and are known as unclassified seizures.

Focal seizures

There are two main types of focal seizure.

Focal aware seizures

Focal aware seizures are where you remain fully conscious throughout.

Symptoms of a focal aware seizure can include:

  • a general strange feeling that is hard to describe
  • a "rising" feeling in your tummy – sometimes likened to the sensation in your stomach when on a fairground ride
  • an intense feeling that events have happened before (déjà vu)
  • experiencing an unusual smell or taste
  • a tingling sensation, or "pins and needles", in your arms and legs
  • a sudden intense feeling of fear or joy
  • stiffness or twitching in part of the body, such as an arm or hand

These seizures are sometimes known as "warnings" or "auras", because they can be a sign that another type of seizure is on its way. This can give you time to warn people around you and make sure you're in a safe place.

Focal impaired awareness seizures

Focal impaired awareness seizures are when you lose your sense of awareness. You won't remember what happened after this type of seizure.

The symptoms of a focal impaired awareness seizure can involve random bodily behaviour, like:

  • smacking your lips
  • rubbing your hands
  • making random noises
  • moving your arms around
  • picking at clothes
  • fiddling with objects
  • adopting an unusual posture
  • chewing or swallowing

During a focal impaired awareness seizure, you'll not be able to respond to anyone else. You'll usually have no memory of it.

Generalised seizures

There are 6 main types of generalised seizure.


Absence seizures mainly affect children, but they also occur in adults. They cause the person to lose awareness of their surroundings, usually for up to 15 seconds. The person will seem to stare vacantly into space. Some people will flutter their eyes or smack their lips. The person will have no memory of the seizure.

Absences can occur several times a day. They may affect a child's performance at school. They can be dangerous if they occur at a critical time, like crossing a busy road.

Myoclonic seizures

These types of seizures cause your arms, legs or upper body to jerk or twitch, as if you have received an electric shock. They often only last for a fraction of a second, and you'll normally remain conscious during this time.

Myoclonic jerks often happen in the first few hours after waking up. They can occur in combination with other types of generalised seizures.

Clonic seizures

These cause the same sort of twitching as myoclonic jerks, except the symptoms will last longer, normally up to 2 minutes. You might lose consciousness during a clonic seizure.

Atonic seizures

Atonic seizures cause all your muscles to relax suddenly. There's a chance you may fall to the ground and you could injure yourself.

Tonic seizures

Tonic seizures cause all your muscles to suddenly become stiff. You might lose balance and fall over. Like atonic seizures, there's a risk of injury.

Tonic-clonic seizures

Tonic-clonic seizures or convulsions have 2 stages. Your body will initially become stiff and then your arms and legs will begin twitching. You'll lose consciousness and some people will wet themselves. The seizure normally lasts a minute, but can last longer.

This type of seizure is what most people think of as an epileptic fit.

Myoclonic-tonic-clonic seizures and Myoclonic-atonic are seizures involving a combination of the generalised seizures above.

What to do if someone has a seizure

If you see someone having a seizure, there are some things you can do to help. It will not usually be necessary to call an ambulance after a seizure.

Immediate action required: Phone 999 if:

  • the seizure has not stopped after 5 minutes
  • the person has more than one seizure without recovering in between
  • you know it's the person's first seizure
  • the person is injured, has breathing problems, or needs emergency medical attention for any other reason
  • the person’s behaviour after a seizure is unsafe

If you're with someone who has a seizure:

  • protect them from injury by removing any dangerous or potentially harmful objects nearby
  • cushion their head with your hands or soft material
  • do not restrain them or attempt to move them (unless they are in immediate danger)
  • don't put anything in their mouth
  • stay calm, and stay with them until they regain consciousness

When the convulsions have stopped, put them into the recovery position until they've recovered.

Status epilepticus

Status epilepticus is the name for any seizure that lasts longer than 5 minutes, or a series of seizures where the person does not regain consciousness in between. This is a medical emergency and requires treatment as soon as possible.

You can be trained to treat status epilepticus if you care for someone with epilepsy. It's important to phone 999 for an ambulance immediately if you suspect status epilepticus.

If you've been trained to treat the condition, you'll usually have been advised to use either:

  • a medication called buccal midazolam that comes in liquid form and is given by trickling the liquid onto the inside of the person's cheek or up their nose (this is the most common immediate treatment)
  • a medication called diazepam that's placed in the person's rectum (less commonly used)

If you've tried one of these treatments and the seizures are continuing, phone 999 for an ambulance.

Causes of epilepsy

In some cases of epilepsy a cause cannot be found.

If there's an identifiable cause, it usually involves the brain being affected by a condition.

The brain is a delicate mix of nerve cells, electrical impulses and chemicals, known as neurotransmitters. Any damage has the potential to disrupt the workings of the brain and cause seizures.

The categories of epilepsy can be separated by their causes which might be:


Causes of structural epilepsy can include:


A genetic abnormality can cause epilepsy. Research has found more genetic causes of epilepsy.

Sometimes epilepsy is hereditary (passed on from one or both parents) or it can be a new gene abnormality.


Infections like meningitis can cause damage to the brain which can result in epilepsy. Viral infections like HIV can also cause epilepsy.


Sometimes epilepsy is caused by an imbalance of the bodies chemicals. This is very rare.


Autoimmune conditions that cause encephalitis (inflammation of the brain) can cause someone to develop epilepsy.


In many cases, no cause of epilepsy is found. This may be because medical investigations are not advanced enough to identify the cause.

Seizure triggers

For many people with epilepsy, seizures can occur without any obvious trigger. However, certain circumstances or the use of certain substances can sometimes come before a seizure. These include:

  • stress
  • lack of sleep
  • withdrawal from alcohol following heavy drinking
  • some medications
  • illegal drugs
  • your menstrual cycle or period
  • flashing lights (this is an uncommon trigger that affects less than 5% of people with epilepsy, and is known as photosensitive epilepsy)

Keeping a seizure diary is a good way to help find out what might trigger your seizures. Every time you have a seizure, record it and make a note of what you were doing. Over time, you might notice some avoidable things that seem to trigger your symptoms.

Diagnosing epilepsy

Epilepsy is usually difficult to diagnose quickly. In most cases, it cannot be confirmed until you have had more than one seizure.

It can be difficult to diagnose because many other conditions, like fainting, migraines and panic attacks, can cause similar symptoms.

If you've had a seizure, you'll be referred to a specialist in epilepsy. This will normally be a neurologist (a doctor who specialises in conditions affecting the brain and nervous system).

Describing your seizures

Some of the most important pieces of information needed to diagnose epilepsy are the details about your seizures.

The doctor will ask you what you can remember and any symptoms you may have had before it happened - things like feeling strange before the seizure or experiencing any warning signs. It is extremely useful to talk to anyone who seen your seizure and ask them exactly what they saw, especially if you cannot remember.

The doctor will also ask about your medical and personal history. They'll ask whether you use any medicines, drugs or alcohol.

The doctor may be able to make a diagnosis of epilepsy from the information you give. They might run further tests like an electroencephalogram (EEG) or magnetic resonance imaging (MRI) scan.

Even if these tests don't show anything, it's still possible that you have epilepsy based on your symptoms and description of your seizures.

Magnetic resonance imaging (MRI) scan

An MRI scan is a type of scan which uses strong magnetic fields to produce detailed images of the inside of your body.

It can be useful in cases of suspected epilepsy. It can often detect possible causes of the condition, such as defects in the structure of your brain.

Electroencephalogram (EEG)

An EEG test can detect unusual brain activity associated with epilepsy. It measures the electrical activity of your brain through electrodes placed on your scalp.

During the test, you may be asked to breathe deeply or close your eyes and you may be asked to look at a flashing light. The test will be stopped immediately if it looks like the flashing light could trigger a seizure.

In some cases, an EEG may be carried out while you're asleep (sleep EEG). Or you may be given a small, portable EEG recording device to monitor your brain activity over 24 hours (ambulatory EEG).

You might be asked to come into the hospital for a few days to have a video telemetry and EEG. During this, an EEG and video will be used to monitor you.

Treating epilepsy

Most people with epilepsy can be successfully treated with anti-seizure medication (ASMs). ASMs do not cure epilepsy, but can prevent seizures from occurring.

There are many different ASMs. They work by changing the levels of the chemicals in your brain that conduct electrical impulses. This reduces the chance of a seizure.

The type of ASM recommended for you will depend on a number of factors like:

  • the type of seizures you have
  • your age
  • whether there are any concerns about a certain ASM interacting with other medicines (like the contraceptive pill)
  • whether you're thinking of having a baby

Examples of commonly used ASMs include sodium valproate, carbamazepine, lamotrigine and levetiracetam.

Taking ASMs

ASMs are available in different forms, including tablets, capsules, liquids and syrups.

It's important you follow any advice about when to take ASMs and how much to take. Never suddenly stop taking an ASM because it could cause a seizure.

You shouldn't take any other medicines whilst taking ASMs without speaking to your GP or epilepsy specialist. This includes over-the-counter medicines or complementary medicines such as St John's Wort. Other medicines could have a dangerous interaction with your ASM and cause a seizure.

Sodium valproate is not usually prescribed for women of childbearing age. This is because it could cause a baby to have physical defects or developmental problems.

It can be used if there is no alternative, or if your specialist has assessed you and it's unlikely you'll respond to or tolerate other treatments. Your specialist or GP will also need to check you're using a reliable form of contraception. Learn more about the risks of valproate medicines during pregnancy.

Side effects are common when starting treatment with ASMs. They're usually short-lived and pass in a few days.

Speak to your healthcare team for more information on the side effects.

Brain surgery

If your epilepsy is still poorly controlled after trying treatment with ASMs, you may be referred to a specialist epilepsy centre. They'll assess if you're suitable for surgery.

This involves having various types of brain scans to find out where the epilepsy is focused. Memory and psychological tests will assess how the surgery might affect you.

Surgery is only recommended when:

  • a single area of the brain is causing seizures (focal seizures)
  • removing that part of the brain would not cause any significant loss of brain function

Most people recover from the effects of surgery after a few days. But it could be several months before you're feeling fit and able to return to work.

Alternative procedures

Your doctor might suggest an alternative procedure if:

  • your epilepsy is still poorly controlled after trying treatment with ASMs
  • brain surgery is not suitable for you

This might be vagus nerve stimulation (VNS).

Vagus nerve stimulation (VNS)

VNS involves surgically implanting a small electrical device under your skin, near your collarbone. The device is like a pacemaker.

The device has a wire that's wrapped around one of the nerves in the left side of your neck, known as the vagus nerve. The device passes a regular dose of electricity to the nerve to stimulate it. This can help reduce the frequency and severity of seizures.

If you feel the warning sign of a seizure coming on, you can activate an extra "burst" of stimulation. This might prevent the seizure from occurring. The stimulation normally occurs every five minutes and lasts for 30 seconds.

How and why VNS works is not fully understood. It's thought that stimulating the vagus nerve alters the chemical transmissions in the brain.

Most people who undergo VNS still need to take ASMs.

The battery for the VNS device typically lasts up to 10 years. After 10 years you'll need another procedure to replace it.

Ketogenic diet

A ketogenic diet is a diet high in fats and low in carbohydrates and protein. It's thought that it may make seizures less likely by altering the chemical composition of the brain.

A ketogenic diet is sometimes advised for children with seizures that are difficult to control and have not responded to ASMs. This is because it's reduces the number of seizures in some children. It should only be used under the supervision of an epilepsy specialist with the help of a dietitian.

It can also be effective in adults with certain types of epilepsy.

Living with epilepsy

Regular exercise and a healthy diet are recommended for everyone. They can help prevent many conditions, including heart disease and many forms of cancer.

Try to eat a balanced diet, containing all the food groups, to give your body the nutrition it needs. Exercising regularly can increase the strength of your bones, relieve stress and reduce fatigue.


Alcohol can also interact with anti-seizure medication (ASMs). ASMs can heighten the effects of alcohol. Alcohol also can make the side effects of ASMs worse and make the medication less effective.

Heavy drinking can disrupt your sleep patterns. This increases your chances of having a seizure. Drinking no more than the recommended daily limits may help reduce this risk.

Read more about drinking and alcohol


Some anti-seizure medication (ASMs) can reduce the effectiveness of some types of contraception. This includes:

If you're sexually active and do not want to become pregnant, ask your GP or epilepsy specialist if your ASMs could affect your contraception.

You may need to ensure you or your partner use another form of contraception like a condom or intrauterine device (IUD).

The effectiveness of the ASM lamotrigine may be reduced if you're taking the combined oral contraceptive pill.

Some ASMs can make the emergency contraceptive pill less effective. If you need emergency contraception, you may need an IUD. Your GP, family planning clinic or pharmacist should be able to help you.


There's no reason why women with epilepsy cannot have a healthy pregnancy.

It's better if the pregnancy is planned because there's a slightly higher risk of complications. With forward planning, you can minimise these risks.

The main risk is that some ASMs increase the chances of a serious birth defect, like spina bifida, cleft lip or congenital heart disease. The risks depend on the type of ASM and the dose you're taking.

The UK Epilepsy and Pregnancy Register can provide more information and advice about the use of ASMs during pregnancy.

If you're planning a pregnancy, talk to your epilepsy specialist. It may be possible to change the ASM you're taking to minimise risks. Taking 400 micrograms (mcg) of a folic acid supplement each day can also help reduce risks of birth defects. You might be recommended to take more than this by your healthcare team.

If you discover you're pregnant, do not stop taking your medicine. The risks to your baby from uncontrolled seizures are far higher than any risks associated with your medicines.

If you're breastfeeding or planned to breastfeed, discuss the medication you're taking with your healthcare team or midwife.

Children and epilepsy

Many children with well-controlled epilepsy can learn and take part in their school’s activities unaffected by their condition. Others may need extra support to get the most out of their time at school.

Make sure your child’s teachers know about their condition and the medication they need to control it.

Epilepsy is more common among children with learning disabilities and special educational needs. These children are entitled to extra help to overcome their difficulties.


You must tell the Driving and Vehicle Licence Authority (DVLA) if you've had any epileptic seizures or blackouts. You must stop driving right away. If you ignore these regulations, you might be prosecuted.

The DVLA may wish to contact your GP or epilepsy specialist.

The DVLA may issue a licence if your seizures have never caused you to lose awareness or affected your ability to safely control a vehicle.

Your GP has a legal responsibility to inform the DVLA if they feel that your driving is putting both you and others at risk.

Read about epilepsy and driving on the DVLA website

Sudden unexpected death in epilepsy (SUDEP)

When somebody with epilepsy dies and there's no clear cause, it's known as sudden unexpected death in epilepsy (SUDEP).

The risk of SUDEP for someone with epilepsy is low.

The exact causes of SUDEP are unknown. It's not possible to predict who it will affect. One theory is that seizures could affect the person's breathing and heartbeat.

Things that may lead to SUDEP include:

  • having seizures which cause loss of consciousness and the body to go stiff and jerk (tonic-clonic seizures)
  • poorly controlled epilepsy, such as not using ASMs prescribed to control seizures
  • having sudden and frequent changes to ASMs
  • being a young adult (in particular male)
  • having sleep seizures
  • having seizures when alone
  • drinking large amounts of alcohol

If you're worried that your epilepsy is poorly controlled, contact your epilepsy specialist. It may be possible to refer you to a specialist epilepsy centre for further treatment.

A charity called SUDEP Action can offer advice and support on SUDEP. They have a helpline for people who have lost a loved one as a result of epilepsy.

Last updated:
10 May 2023