Epilepsy is a brain condition that causes repeated seizures

Epilepsy is a neurological disorder—meaning it affects the brain—in which a person has a tendency to have seizures repeatedly over time. A seizure happens when there is a sudden burst of electrical activity in the brain that disrupts normal function. During a seizure, a person may lose consciousness, experience muscle jerking or stiffness, or have unusual sensations or emotions. Not everyone who has one seizure has epilepsy; epilepsy is diagnosed when seizures happen more than once, usually without an obvious trigger that won't happen again.

The seizures in epilepsy can look very different from person to person. Some people lose awareness and their body goes rigid or jerks uncontrollably. Others stay awake but feel confused, see flashing lights, or experience tingling in their limbs. Some seizures last a few seconds; others last several minutes. The type of seizure depends on which part of the brain the electrical activity starts in and how far it spreads.

Key Takeaways

  • Epilepsy is diagnosed when a person has two or more seizures that are not caused by a temporary condition like fever or low blood sugar.
  • Seizures happen because of abnormal electrical activity in the brain, and the type of seizure depends on where in the brain the activity occurs.
  • A doctor diagnoses epilepsy using an EEG (electroencephalogram), which records brain waves, along with a medical history and sometimes an MRI or CT scan.
  • Most people with epilepsy can control their seizures with medication, though some may need surgery or other treatments if medication does not work.
  • Epilepsy affects people of all ages, but it is most common in children under 5 and in adults over 60.

What causes seizures in epilepsy

The brain works by sending electrical signals between nerve cells. In epilepsy, something disrupts this normal pattern and causes a sudden, uncontrolled burst of electrical activity. This can happen for many reasons. Some people are born with brain differences that make seizures more likely. Others develop epilepsy after a brain injury, stroke, infection, or tumor. In many cases, doctors cannot find a specific cause—this is called idiopathic epilepsy.

Certain things can trigger a seizure in someone with epilepsy, though triggers vary widely. Common triggers include lack of sleep, stress, flashing lights, missed medication doses, or hormonal changes. Not everyone with epilepsy has the same triggers, and some people have no identifiable triggers at all. Understanding your own triggers, if you have them, is an important part of managing the condition.

Types of seizures and where they start in the brain

Doctors classify seizures based on where the abnormal electrical activity begins. Focal seizures start in one area of the brain. During a focal seizure, a person may stay awake and aware, or they may lose consciousness. They might feel tingling, see flashing lights, or experience fear or déjà vu. The person may not remember what happened during the seizure.

Generalized seizures involve electrical activity across both sides of the brain at once. The most common type is a tonic-clonic seizure, in which the body first goes stiff (the tonic phase) and then jerks rhythmically (the clonic phase). The person loses consciousness and may not remember the seizure afterward. Other generalized seizures include absence seizures, which cause brief lapses in awareness, and atonic seizures, in which the person suddenly loses muscle tone and may fall.

How doctors diagnose epilepsy

A doctor diagnoses epilepsy by taking a detailed history of the seizures and then using tests to record brain activity. The first step is usually a conversation about when the seizures started, what they look like, how long they last, and whether anything seems to trigger them. The doctor will also ask about family history, past illnesses or injuries, and current medications.

The main test for epilepsy is an EEG (electroencephalogram). This test uses small metal discs called electrodes placed on the scalp to record the brain's electrical activity. The test is painless and takes 20 to 40 minutes. An EEG can show abnormal patterns that suggest epilepsy, even when the person is not having a seizure at that moment. Some doctors use a longer EEG that records for hours or days to catch seizure activity.

A doctor may also order an MRI (magnetic resonance imaging) or CT (computed tomography) scan to take detailed pictures of the brain and look for structural problems like scars, tumors, or abnormal development. Blood tests may be done to rule out other causes of seizures, such as low blood sugar or infection. In some cases, a doctor may refer you to a neurologist—a doctor who specializes in brain and nervous system disorders—for further testing and diagnosis.

What happens after an epilepsy diagnosis

Once epilepsy is diagnosed, the main goal is to control seizures with treatment. Most people start with medication called anti-seizure drugs or antiepileptic drugs (AEDs). These medications work by calming abnormal electrical activity in the brain. There are many different medications available, and finding the right one or combination often takes time. A doctor may start with one medication at a low dose and increase it gradually, or try different medications until seizures are controlled.

About 70 percent of people with epilepsy can control their seizures with medication, though this percentage varies depending on the type of epilepsy and other factors. For people whose seizures do not respond well to medication, other treatments exist. Brain surgery can remove the area of the brain where seizures start, if doctors can pinpoint it. Vagus nerve stimulation uses a small device implanted under the skin to send electrical pulses to a nerve in the neck. Ketogenic diet—a high-fat, low-carbohydrate diet—can reduce seizures in some people, especially children.

Living with epilepsy and managing seizure risk

Managing epilepsy involves taking medication as prescribed, keeping track of seizures, and identifying and avoiding triggers when possible. Many people keep a seizure diary to record when seizures happen, what they felt before or during the seizure, and what they were doing beforehand. This information helps doctors adjust treatment and helps you understand your own patterns.

Safety is an important consideration. People with epilepsy should avoid activities that could be dangerous if a seizure occurs, such as swimming alone or driving (depending on local laws and how well seizures are controlled). Wearing a medical alert bracelet or necklace can help others know what to do if a seizure happens in public. Most people with well-controlled epilepsy can work, go to school, exercise, and live full lives. Talking openly with family, friends, and employers about the condition helps build understanding and support.

Epilepsy in children and older adults

Epilepsy can start at any age, but it is most common in young children and in people over 60. In children, epilepsy may be caused by birth defects, genetic conditions, or brain injury during birth. Some types of childhood epilepsy improve or resolve as the child grows, while others persist into adulthood. Children with epilepsy can usually attend school and participate in activities, though parents and teachers should know how to respond if a seizure occurs.

In older adults, epilepsy is often caused by stroke, dementia, or other age-related brain changes. Older adults may also be taking other medications that can interact with anti-seizure drugs, so treatment requires careful monitoring. Despite these challenges, many older adults with epilepsy can manage the condition effectively and maintain their independence with proper medical care.

Frequently Asked Questions

Is one seizure the same as epilepsy?

No. A single seizure does not mean a person has epilepsy. Epilepsy is diagnosed when someone has two or more seizures that are not caused by a temporary, reversible condition like fever, low blood sugar, or alcohol withdrawal. Many people have one seizure in their lifetime and never have another.

Can epilepsy be cured?

Epilepsy cannot be cured, but it can be controlled. About 70 percent of people with epilepsy become seizure-free with medication. Some people eventually stop having seizures and may be able to stop taking medication under a doctor's supervision. Others manage the condition long-term with ongoing treatment.

Is epilepsy inherited?

Some types of epilepsy run in families and have a genetic basis, but most epilepsy is not directly inherited. Having a family member with epilepsy increases the risk slightly, but most children of parents with epilepsy do not develop the condition. A genetic counselor can discuss risk if you have concerns.

Can seizures cause brain damage?

Most individual seizures do not cause permanent brain damage. However, very long seizures or repeated seizures that are not treated can potentially harm the brain. This is why getting a diagnosis and starting treatment promptly is important. With proper medication and management, most people with epilepsy do not experience brain damage.

Can someone with epilepsy drive?

Driving rules for people with epilepsy vary by state and country. Generally, a person must be seizure-free for a certain period (often three to six months) before driving is permitted. A doctor can advise whether it is safe for you to drive based on your seizure control and local laws.