Overview
Epilepsy is a neurological condition characterised by a tendency to have recurrent seizures. A seizure occurs when there is a sudden burst of abnormal electrical activity in the brain. Seizures vary widely in appearance from brief absences to full convulsions. Epilepsy can usually be well controlled with medication.
How common is it?
About 600,000 people in the UK have epilepsy. It is the most common serious neurological condition, affecting people of all ages.
Causes and risk factors
Epilepsy can result from brain injury, abnormal brain development, or a genetic tendency for neurons to discharge abnormally. In many cases no cause is found.
Common risk factors
- Previous brain injury, stroke, or infection (meningitis, encephalitis)
- Brain tumours
- Genetic epilepsy syndromes
- Structural brain abnormalities
- Birth injury or oxygen deprivation
- Alzheimer's disease in older adults
- Unknown cause (about 40% of cases)
Symptoms
- Brief staring spells and loss of awareness (absence seizures)
- Sudden jerking movements of the arms and legs
- Full convulsion with muscle stiffening and rhythmic jerking (tonic-clonic seizure)
- Falling without warning
- Repetitive movements such as lip-smacking or hand rubbing (focal seizures)
- Confusion and tiredness after a seizure
- Warning sensations before a seizure (aura): smell, taste, feeling of fear
When to see a doctor
Call emergency services (999 in the UK) for a first seizure, a seizure lasting longer than usual or more than five minutes when the usual duration is unknown, repeated seizures without recovery, serious injury, breathing difficulty, or failure to regain consciousness. Do not wait 20 minutes to seek help. Follow an established emergency care plan if you are trained to do so. If a possible first seizure has already ended and no hospital assessment occurred, seek urgent medical advice.
Diagnosis
A specialist assesses the history, witness account and examination. Tests may include an ECG, blood tests, EEG and brain imaging. An EEG can support the diagnosis, but a normal result does not rule out epilepsy. Low blood glucose and other conditions can also cause seizures.
Treatments
Anti-seizure medication
The mainstay of treatment. Around 70% of people with epilepsy achieve good seizure control with one or two medications. Drug choice depends on seizure type, sex, age, and side effect profile.
Epilepsy surgery
For people with focal epilepsy where a clear seizure focus is identified on MRI and EEG, surgery to remove the focus can be curative in selected cases.
Vagus nerve stimulation or ketogenic diet
For people who cannot take surgery or whose seizures are not controlled with medication. The ketogenic diet (high fat, low carbohydrate) has particularly good evidence in children.
Self-care and lifestyle
- Take medication at the same time every day and never stop abruptly
- Ensure adequate sleep as sleep deprivation commonly triggers seizures
- Avoid alcohol excess and recreational drugs
- Inform DVLA and observe the driving regulations (1 year seizure-free for most licences)
- During a convulsive seizure, clear nearby hazards, cushion the head and time the episode. After the shaking stops, place the person on their side and stay with them. Put nothing in their mouth and give no food or drink until they have fully recovered.
Prevention
Epilepsy cannot always be prevented. Protecting against head injury and managing conditions that can damage the brain are useful precautions. Fever-related seizures in children are different from epilepsy; treating a fever should not be presented as a proven way to prevent epilepsy.
Sources for targeted updates
Updated: 11 September 2026. Emergency seizure advice, diagnostic limits and prevention wording. This update covers the named sections; a full review of the remaining guide is pending.