Epilepsy is a long-term, noncommunicable disease of the brain in which bursts of excessive electrical activity in groups of brain cells cause repeated seizures. It affects people of all ages, around 50 million people worldwide, and between 4 and 10 of every 1,000 people have active epilepsy at any given time. A single seizure is not epilepsy: up to 10% of people have one seizure in their lifetime. Causes include brain damage before or around birth, severe head injuries, strokes and brain infections such as meningitis or neurocysticercosis, but in about half of all cases no cause is found. People living with epilepsy face a risk of premature death up to three times that of the general population, and many also live with anxiety, depression or other health conditions.
Treatment is effective and cheap. Up to 70% of people living with epilepsy could become seizure-free with antiseizure medicines, which can cost as little as US$5 a year, and most people can be diagnosed and treated in primary health care without sophisticated equipment. Yet nearly 80% of people with epilepsy live in low- and middle-income countries, and in low-income countries about three quarters of them do not get the treatment they need. Myths that epilepsy is contagious or incurable keep people from seeking care. Many children with epilepsy do not go to school, adults are denied jobs, driving licences or marriage, and in some countries the law still allows a marriage to be annulled because one partner has epilepsy.
How epilepsy and the treatment gap are measured
Epilepsy is diagnosed clinically, mainly from a description of the seizures, and is counted in population surveys, health records and modelled estimates. The main measures are:
Active epilepsy
People who have epilepsy and have had seizures recently or are taking medicine for them. WHO puts the share of the population with active epilepsy at 4 to 10 per 1,000 at any given time. One seizure on its own does not count as epilepsy.
Treatment gap
The share of people with active epilepsy who need treatment but do not receive it. Many countries have no recent national estimate, so global figures are broad: WHO reports gaps above 75% in most low-income countries and above 50% in most middle-income countries.
Service coverage
Under WHO's action plan for 2022–2031, countries report how many people with epilepsy are reached by services, so that the target of raising coverage by 50% can be tracked. The first global baselines, for 2022, were published in 2025 with data from 102 of 194 WHO Member States.
The 90-80-70 cascade
The action plan's indicators follow people through care: by 2031, 90% of people with epilepsy should know they have a treatable brain disorder, 80% should have access to affordable, safe antiseizure medicines, and 70% of those treated should have their seizures adequately controlled.