Epilepsy affects the brain and causes repeated seizures, also known as fits.

Epilepsy affects around 456,000 people in the UK. This means that about 1 in 130 people has epilepsy. Epilepsy usually begins during childhood, although it can start at any age.

Seizures

The cells in the brain, known as neurons, communicate with each other with electrical impulses. During a seizure, the electrical impulses are disrupted, which can cause the brain and body to behave strangely.

The severity of the seizures can differ from person to person. Some people simply experience a ‘trance-like’ state for a few seconds or minutes, while others lose consciousness and have convulsions (uncontrollable shaking of the body).

Types of epilepsy

There are three main types of epilepsy:

• Symptomatic epilepsy - the symptoms of epilepsy are due to damage or disruption to the brain.
• Cryptogenic epilepsy - while no evidence of damage to the brain can be found, other symptoms, such as learning difficulties, suggest that damage to the brain has occurred.
• Idiopathic epilepsy - no obvious cause for epilepsy can be found.

See Epilepsy - causes for more information about the different types of epilepsy.

Outlook

Epilepsy is a long-term condition and, for most people, the outlook is very good. Symptoms can usually be controlled using medicines known as anti-epileptic drugs (AEDs).

It can take some time to find the right type and correct dose of AED before your seizures can be controlled.

With a clear understanding of your epilepsy and good management of your seizures, the risk of SUDEP can be minimised.

Want to know more?

• Epilepsy Action: What is epilepsy?
• The National Society for Epilepsy: What is epilepsy?
• Brain & Spine Foundation: Epilepsy.

The main symptoms of epilepsy are repeated seizures. There are about 40 different types of seizure, and how they affect you depends on which areas of your brain are affected.

People with epilepsy can experience any of the varieties of seizures, although most people follow a consistent pattern of symptoms. This pattern is known as an epilepsy syndrome.

Doctors who treat epilepsy classify seizures by how much of the brain is affected. There are:

• partial seizures, where only a small part of the brain is affected
• generalised seizures, where most or all of the brain is affected

Partial seizures

There are two types of partial seizure:

• simple partial seizure, where you remain fully conscious throughout
• complex partial seizure, where you lose your sense of awareness and can’t remember what happened after the seizure has passed

Symptoms of a simple partial seizure include:

• changes in the way things look, smell, feel, taste or sound
• an intense feeling that events have happened before (déjà vu)
• a tingling sensation, or ‘pins and needles’, in your arms and legs
• a sudden intense emotion, such as fear or joy
• the muscles in your arms, legs and face may become stiff
• you may experience twitching on one side of your body

The symptoms of a complex partial seizure normally involve apparently strange and random bodily behaviour, such as:

• 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 complex partial seizure, you will not be able to respond to anyone else, and you will have no memory of the event.

Complex partial seizures are quite common and account for 2 in 10 of all seizures experienced by people with epilepsy.

Generalised seizures

In most cases, a person having a generalised seizure will be completely unconscious.

There are six main types of generalised seizure.

Absences

Absence seizures mainly affect children. They cause the child to lose awareness of their surroundings for up to 20 seconds. The child will seem to stare vacantly into space, although some children will flutter their eyes or smack their lips. The child will have no memory of the seizure.

Absences can occur several times a day. Although they are not dangerous, they may affect the child's performance at school.

Myoclonic jerks

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

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

Clonic seizure

This causes the same sort of twitching as myoclonic jerks, except the symptoms will last longer, normally up to two minutes. Loss of consciousness may occur.

Atonic seizure

Atonic seizures cause all your muscles to suddenly relax, so there is a chance you will fall to the ground. Facial injuries are common with this type of seizure.

Tonic seizure

Unlike an atonic seizure, tonic seizures cause all the muscles to suddenly become stiff. You can lose balance and fall over, so injuries to the back of the head are common.

Tonic-clonic seizure

A tonic-clonic seizure has two stages. Your body will become stiff and then your arms and legs will begin twitching. You will lose consciousness and some people will wet themselves. The seizure normally lasts between one and three minutes but they can last longer.

This is the most common type of seizure, and about 60% of all seizures experienced by people with epilepsy are tonic-clonic seizures.

Tonic-clonic seizures are what most people think of as an epileptic fit.

Auras

People who have epilepsy often get a distinctive feeling or warning sign that a seizure is on its way. These warning signs are known as auras, but they are actually simple partial seizures.

Auras differ from person to person, but some common auras include:

• noticing a strange smell or taste
• having a feeling of déjà vu
• feeling that the outside world has suddenly become unreal or dreamlike
• experiencing a sense of fear or anxiety
• your body suddenly feeling strange

Although this warning cannot prevent the seizure, it can give you time to warn people around you and make sure you are in a safe place.

Want to know more?

• Epilepsy Action: Seizures.
• The National Society for Epilepsy: Epileptic seizures. 

Status epilepticus

Status epilepticus is a seizure that lasts longer than 30 minutes or a series of seizures where the person does not regain consciousness in between. If a seizure lasts longer than five minutes, call 999 for an ambulance.

Status epilepticus can be treated with diazepam given as an injection or through someone's rectum. An alternative treatment is a medication called buccal midazolam. This comes in liquid form and it is administered by trickling the liquid onto the inside of your cheek. It is then absorbed into your bloodstream.

You do not have to be a healthcare professional to do this, but you do need the correct training as well as permission from the person who has epilepsy. If you care for someone with epilepsy, you can be trained to administer rectal diazepam or buccal midazolam in case status epilepticus occurs.

Want to know more?

• Epilepsy Action: Status epilepticus.

Epilepsy can have a number of causes. The brain is a delicate mix of neurons (brain cells), electrical impulses and chemicals, known as neurotransmitters. Any damage has the potential to disrupt the workings of the brain and cause seizures.

There are three main categories of epilepsy:

• Symptomatic epilepsy - there is a known cause for a person’s epilepsy, such as a head injury.
• Idiopathic epilepsy - despite investigation, no apparent cause for epilepsy can be found.
• Cryptogenic epilepsy - like idiopathic epilepsy, no apparent cause can be found. However, there is strong evidence that this type of epilepsy may be the result of brain damage, which may also cause other problems, such as learning difficulties.

Symptomatic epilepsy

Causes of symptomatic epilepsy include:

• conditions that affect the structure of the brain, such as cerebral palsy
• drug and alcohol misuse
• birth defects
• problems during birth which cause a baby to be deprived of oxygen, such as the umbilical cord getting twisted or compressed during labour
• infectious conditions that can damage the brain, such as meningitis 
• head injuries
• strokes
• brain tumours

Idiopathic epilepsy

Where no apparent cause for epilepsy can be found, many researchers have suggested that small genetic changes in the brain could be the cause of epilepsy. Current research is looking for defects in certain genes that may affect electrical transmission in the brain.

While a number of studies have been carried out, no strong association has been found between any particular genes and the development of epilepsy.

Cryptogenic epilepsy

The term cryptogenic epilepsy is used when no definite cause for epilepsy can be found but there is strong evidence that the symptoms are due to damage or disruption to the brain.

Evidence that suggests a person has cryptogenic epilepsy includes:

• They have learning difficulties.
• They have a developmental condition, such as autistic spectrum disorder.
• They have unusual electroencephalogram (EEG) readings (an EEG is a device that measures the electrical activities of the brain).

Want to know more?

• The National Society for Epilepsy: Causes of epilepsy.

Triggers

Many people with epilepsy find that certain circumstances or substances can trigger a seizure. These triggers include:

• stress
• lack of sleep
• alcohol, particularly binge drinking and during a hangover
• illegal drugs such as cocaine, amphetamines, ecstasy and any opiate-based drugs, such as heroin, methadone or codeine
• health conditions that cause a high temperature (fever)
• flashing lights (this is an uncommon trigger that affects only 5% of people with epilepsy, and is also known as photosensitive epilepsy)

Some women may be more prone to seizures just before, during or after their period. This is because the hormones released by the body during that time can affect the chemicals in the brain, making seizures more likely.

Want to know more?

• Epilepsy Action: Possible seizure triggers.

Seizure threshold

Most people with epilepsy have a seizure threshold. This is the point at which the brain’s natural resistance to seizures is passed, triggering a seizure.

People with a low seizure threshold experience frequent seizures and are very sensitive to triggers. People with a high seizure threshold experience less frequent seizures and triggers will have less effect on them.

Epilepsy can be difficult to diagnose because many other conditions, such migraines and panic attacks, can cause similar symptoms.

If you have had a seizure, you will be referred to a specialist in epilepsy, normally a neurologist (a doctor who specialises in conditions that affect the nervous system).

The doctor will ask you what you can remember about the seizure and any symptoms you may have had before it happened, such as feeling strange before the seizure or experiencing any warning signs. It may be useful to talk to anyone who witnessed your seizure and ask them exactly what they saw, especially if you cannot remember the seizure.

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

The doctor should be able to make a diagnosis of epilepsy from the information you give, but they may run further tests.

You may need an electroencephalogram (EEG), which can detect unusual brain activity associated with epilepsy. Or you may have a magnetic resonance imaging (MRI) scan, which can spot any defects in the structure of your brain.

Electroencephalogram (EEG)

An EEG test 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, as these actions could reveal unusual brain activity associated with epilepsy.

You may also be asked to look at a flashing light, but the test will be stopped immediately if it looks like the flashing light could trigger a seizure.

Magnetic resonance imaging (MRI) scan

An MRI scan can often detect possible causes of epilepsy, such as defects in the structure of your brain or the presence of a brain tumour.

Want to know more?

• The National Society for Epilepsy: Diagnosis. 
• Epilepsy Action: Getting a diagnosis.