What is epilepsy?

Epilepsy¹ is a chronic disorder that affects the central nervous system (referred to as a neurological disorder). The abnormal brain activity resulting from this disorder causes repeated seizures—unprovoked periods of abnormal symptoms, behavior, or sensations.

There is no one condition that causes epilepsy. The disorder may result from genetic factors, brain injuries, or other conditions that affect the brain. However, in many cases, the exact cause of the disorder is unknown. Ultimately, anyone can develop epilepsy regardless of race, ethnic background, age, and biological sex.

Similarly, the effects of epilepsy can vary greatly from person to person. There are different kinds of seizures, each differing in symptoms and severity. Depending on the type of seizure, some people may appear to “space out” or stare blankly for a few moments, while others may collapse, twitch, or shake violently. No matter the particular features and location of a seizure, however, the electrical events that cause it originate in the brain.

Having one single seizure doesn’t necessarily mean that you have epilepsy: in most cases, a person must have at least two unprovoked seizures in order to be diagnosed with the disorder. Having repeated seizures can have a significant impact on daily life, affecting a person’s ability to work, drive, maintain relationships, and remain safe in their surroundings. Luckily, treatments—including medication and surgery—exist to help control seizures in people with epilepsy. While some people need lifelong treatment for their seizures, others (especially children with epilepsy) outgrow the condition over time.

How common is epilepsy?

According to the CDC, in 2015, 1.2% of the US population² (about 3.4 million people) had active epilepsy.

Adults (aged 18 or older) are said to have active epilepsy if they report having a history of a professionally diagnosed epilepsy or seizure disorder and are currently taking medication to control the disorder, have had one or more seizures in the past year, or both.

Children 17 years of age or younger have active epilepsy if their parent/guardian reports that a healthcare provider has ever told them that their child has epilepsy or a seizure disorder, and their child currently has epilepsy or a seizure disorder.

Different types of seizures

There are several different types of seizures, all of which can be classified into two groups: generalized or focal³. Generally, all types of seizures may last for as long as several minutes.

Generalized seizures, which appear to affect all areas of the brain, include:

• Absence seizures: This type of seizure, previously referred to as a “petit mal seizure,” causes subtle, rapid movements (like blinking or lip-smacking) or a few seconds of appearing to “space out” (blankly staring off into space). Absence seizures may occur in clusters and cause a brief loss of awareness. They also often occur in children with epilepsy.
• Tonic seizures: Tonic seizures cause the muscles to stiffen (most commonly, those in the back and limbs) and may cause one to fall to the ground.
• Atonic seizures: Atonic, or “drop,” seizures cause a sudden loss of muscle control that may cause a person to fall down or collapse.
• Clonic seizures: These seizures, which usually affect the neck, arms, and face, cause the muscles to jerk repeatedly or rhythmically.
• Myoclonic seizures: Myoclonic seizures usually cause brief, sudden jerking or twitching in the limbs.
• Tonic-clonic seizures: Previously known as “grand mal seizures,” tonic-clonic seizures can cause a person to cry out, fall to the ground, have muscle spasms (jerking or shaking), and abruptly lose consciousness. A person who has a tonic-clonic seizure may feel tired or fatigued following an episode.

Focal seizures, also called partial seizures, appear to result from abnormal activity in just one part of the brain. These include:

• Focal seizures without loss of consciousness: Previously known as “partial seizures,” these seizures don’t cause a person to lose consciousness. They may cause a shift in emotions or a change in sensations, affecting the way things look, sound, smell, feel, or taste. They may also cause twitching or involuntary jerking in a body part and spontaneous sensory symptoms, such as tingling, dizziness, or flashing lights.
• Focal seizures with impaired awareness: Once called “complex partial seizures,” these seizures cause altered awareness or a complete loss of consciousness. People experiencing these types of seizures may stare into space and respond unusually to their environments. They may also perform repetitive physical movements, such as swallowing, chewing, wringing their hands, or walking in circles.

The symptoms of focal seizures may be confused with those of other neurological disorders, such as narcolepsy, migraine, or a mental health disorder. For this reason, people who experience these symptoms need thorough examination and testing in order to determine whether they are caused by epilepsy or another disorder entirely.

Epilepsy causes

Epilepsy occurs⁴ when the normal pattern of neuron activity in the brain is disturbed. This abnormal brain activity is what causes the unusual sensations, behaviors, emotions, or movements that occur during seizures.

In some people, the cause of epilepsy is unknown. In fact, in roughly half of those with epilepsy, the disorder has no identifiable cause⁵.

The identifiable causes of epilepsy are numerous. Anything that affects the brain and interrupts the neurons’ normal patterns of activity—from brain damage or illness to abnormal brain development—can result in the disorder. Some possible causes of epilepsy include:

• Genetics: Epilepsy may be categorized into different types depending on the type of seizure experienced or the part of the brain affected. Because certain forms of the disorder run in families, it’s likely that genetics plays a role in the development of epilepsy.

  Research has also found links between certain types of epilepsy and specific genes. Certain genes may also make people with epilepsy more sensitive to environmental factors that can trigger seizures. In most people with epilepsy, however, genes only play a partial role in the cause of the disorder.

• Brain or head trauma: Undergoing a traumatic brain injury or other head trauma can result in epilepsy.

• Brain conditions: Conditions that damage the brain, such as tumors, can cause epilepsy. Stroke, which occurs when the blood supply to your brain is interrupted or reduced, is the leading cause of epilepsy in adults over the age of 35.

• Infections: Certain infectious diseases, such as viral encephalitis, meningitis, and AIDS, can result in epilepsy.

• Developmental disorders: In some cases, epilepsy is associated with developmental disorders like autism or neurofibromatosis.

• Prenatal injury: Unborn babies are sensitive to brain damage and may incur it as the result of several factors, including malnutrition, oxygen deficiencies, or an infection in the mother. The resulting brain damage can lead to epilepsy, as well as cerebral palsy.

Some people may experience a single seizure as the result of a head injury or a high fever (known as a febrile seizure⁶). This does not necessarily indicate that they have epilepsy—the disorder is only diagnosed after someone has had two or more seizures.

Epilepsy and puberty

Research has found that in some women and girls of childbearing age (those who are menstruating), there may be a link between hormones and epileptic seizures⁷.

A woman’s hormone levels may affect her epilepsy, including when it starts, how often she has seizures, and when (or if) she stops experiencing seizures. Specifically, estrogen and progesterone, two female sex hormones, can speed up or slow down brain activity, affecting when a woman experiences seizures.

During puberty, in particular, drastic hormonal changes occur in the body. Because of this, epilepsy commonly occurs during puberty in women.

Additionally, as a woman’s hormone levels change throughout her menstrual cycle, one in three women with epilepsy find that their menstrual periods affect their seizures. Some experience seizures regularly at a certain time during their menstrual cycle (such as right before their period begins or during ovulation). This uncommon form of epilepsy is referred to as catamenial epilepsy⁸.

As a woman’s hormone levels change throughout her life, the approach taken to treating her condition may need to change. Ultimately, epilepsy varies from person to person. Some women’s epilepsy may be affected by their hormone levels, while others’ may not.

Risk factors for epilepsy

Certain non-modifiable (inherent or unchangeable) and modifiable (changeable) factors may increase your risk of having epilepsy, including⁹:

• Age: While the disorder can occur at any age, the onset of epilepsy is most common in childhood and older adulthood.
• Family history: Having a blood relative with epilepsy may increase your risk of developing a seizure disorder, as well.
• Head injuries: Some cases of epilepsy are caused by head and brain injuries. You can reduce your risk of undergoing a traumatic injury by wearing your seatbelt while riding in a car and wearing a helmet while engaging in activities that pose a high risk of head injury (such as biking, riding a motorcycle, or skiing/snowboarding).
• Seizures in childhood: A child’s risk of developing epilepsy increases if they have a long seizure, a nervous system condition, or a family history of epilepsy. While high fevers in childhood may, in some cases, cause seizures, this doesn’t usually lead to epilepsy.
• Brain infections: Having infections that affect the brain, such as meningitis (which causes inflammation in the brain or spinal cord), can increase the risk of developing epilepsy.
• Vascular diseases and stroke: Stroke—the blockage or reduction of blood flow to the brain—and other forms of blood vessel (vascular) diseases can lead to brain damage, in some cases triggering epilepsy. In order to reduce your risk of developing these diseases, practice healthy lifestyle habits, including not smoking, eating a healthy diet, and getting regular physical activity.
• Dementia: Dementia—which describes a decline in cognitive function—can increase the risk of having epilepsy in older adults.

Epilepsy symptoms

The signs and symptoms of epilepsy can vary greatly from person to person. There are different types of seizures, each of which affects the body in certain ways. These different types of seizures can also affect individuals in different ways.

Generally, the symptoms of a seizure are episodic (meaning they come and go in episodes) and stereotypic (they occur in the same or nearly the same way each time). In some cases, however, symptoms may be unpredictable.

Because epilepsy is the result of abnormal brain activity, seizures can affect any processes coordinated by the brain. Common signs and symptoms¹⁰ of seizures (not specific to one type of seizure) include:

• Temporary confusion
• “Staring spells,” during which the person seems to lose focus and stare off into space
• Loss of consciousness or awareness of one’s surroundings
• Uncontrollable muscle spasms or jerking movements in the limbs or body
• Physiological symptoms, such as fear, anxiety, or déjà vu

The symptoms of epilepsy depend on the type of seizure experienced. However, because most people with epilepsy tend to have the same type of seizure every time, they experience similar symptoms from episode to episode.

The three phases of seizures

Seizures have three phases: a beginning, middle, and end¹¹. However, not every phase of a seizure may be easily distinguishable from the next. Additionally, people who have seizures may not go through each stage or experience all of the following symptoms.

The three phases of seizures and their common signs and symptoms include:

Beginning: Some people with epilepsy may not have any warning signs before their seizures. Others, however, may be aware that a seizure is beginning as long as several hours or days beforehand.

Generally, there are two stages of the beginning of a seizure:

• Prodrome: Some people experience the prodrome phase, during which certain sensations, feelings, or changes in behavior indicate that a seizure may be coming. Experiencing these warning signs can help a person prepare for a seizure by making sure they’re in a safe environment, taking their medication, and more.
• Aura: People with certain forms of epilepsy may experience an aura as one of the first symptoms of a seizure. An aura may cause an indescribable feeling, or it may be a recognizable change in thoughts, sensations, or behavior that's similar each time a seizure occurs.

An aura can occur prior to changes in awareness or consciousness. It may also occur alone and be referred to as a focal seizure without loss of consciousness.

Common symptoms before a seizure include:

Changes in awareness, sensations, thoughts, or emotions: Unusual smells, sounds, or tastes “Strange” or indescribable feelings Déjà vu (the feeling that a person, place, or thing is familiar, despite having never experienced it before) or jamais vu (the feeling that a person, place, or thing is new or unfamiliar when it's not) Negative or scary emotions, like fear, panic, or anxiety Racing thoughts Pleasant emotions or sensations

• Physical changes:
  • Headache
  • Nausea or other unusual feelings in the stomach (often described as a “rising” feeling from the stomach to the throat)
  • Dizziness or lightheadedness
  • Numbness or tingling in part of the body

Middle: The middle of a seizure—which correlates with the electrical seizure activity in the brain—is often referred to as the ictal phase. This includes everything from the first symptoms of a seizure (including an aura) to the end of seizure activity.

Common symptoms during a seizure include:

• Changes in awareness, sensations, thoughts, or emotions:
  • Confusion or feeling “spaced out”
  • Distraction or daydreaming
  • Loss of awareness (often called “blackout”) or consciousness (becoming unconscious or “passing out”)
  • Periods of forgetfulness or lapses in memory
  • Sound distortion or inability to hear
  • Unusual tastes or smells (often unpleasant smells, like burning rubber)
  • Blurred vision, loss of vision, or inability to see
  • Visual hallucinations, such as flashing lights or formed visual hallucinations (seeing distinct objects or things that aren’t actually there)
  • Numbness, tingling, or feelings like an electric shock in the body or a limb
  • Out-of-body sensations or feelings of detachment
  • Parts of the body feeling or looking different
  • Déjà vu or jamais vu
  • Fear, panic, or the feeling of impending doom
  • Pleasant feelings
• Physical changes:
  • Difficulty talking (the person may stop talking or make nonsensical or garbled sounds)
  • Repeated blinking, staring, or eyes moving to one side or looking upward
  • Lack of movement or muscle weakness (inability to move, head or body slumping or falling forward)
  • Tremors or twitching/jerking movements (may occur on one or both sides of the face, limbs or entire body; may be confined to one area or start in one area and spread to other parts of the body)
  • Rigidity or tension in the muscles
  • Repeated unintentional movements (automatisms) in the face, arms, or legs, including lip-smacking or chewing motions, walking or running, or repeated movement of the hands (like wringing, playing with objects in the hands, or waving)
  • Repeated purposeful movements (the person may continue the activity they were performing before the seizure)
  • Convulsion (loss of consciousness; the body becomes tense or rigid followed by fast, jerking movements)
  • Sweating
  • Pale or flushed skin
  • Dilated or enlarged pupils
  • Tongue biting (due to teeth clenching when muscles tighten)
  • Difficulty breathing
  • Racing heartbeat
  • Inability to swallow or drooling
  • Incontinence (unexpected loss of control of urine or stool)

Ending: The end of a seizure, known as the postictal phase, is the recovery period. Some people recover immediately following a seizure, while others may need several minutes or hours to start feeling like normal again. The type of seizure and the part of the brain it impacts will affect how long the recovery period takes and what may occur during it.

Common symptoms after a seizure include:

• Changes in awareness, sensations, thoughts, or emotions:
  • Being slow to respond or unable to respond immediately
  • Difficulty talking or writing
  • Sleepiness or confusion
  • Memory loss
  • Feelings of fuzziness, dizziness, or lightheadedness
  • Feelings of fear, anxiety, frustration, embarrassment, or shame
  • Feelings of depression, sadness, or being generally upset
• Physical changes:
  • Headache or other pain
  • Feeling tired, exhausted, or sleepy
  • Weakness in one part or side of the body
  • Thirst
  • Nausea or upset stomach
  • Injuries, such as cuts, bruising, or even broken bones or head injury if the person fell during the seizure
  • Urge to use the restroom or loss of bladder or bowel control

If you or someone you know has epilepsy, seek immediate medical attention if:

• The seizure lasts longer than five minutes
• Breathing or consciousness don’t return after the seizure has ended
• A second seizure occurs immediately after the first
• The person who had the seizure has a high fever, heat exhaustion, is pregnant, or has diabetes
• An injury occurred during the seizure

If you experience any of the signs and symptoms of a seizure (especially for the first time), seek immediate medical attention. If you believe that someone is having a seizure, don’t hesitate to dial 911.

Complications from epilepsy

The most common complications from epilepsy result from the risks posed by having seizures¹². Having a seizure at certain times or in certain situations may put you or others in danger. Some risks associated with having seizures include:

• Falling: Falling during a seizure can cause head injury or broken bones.

• Car accidents: Having a seizure while driving a car or operating other heavy machinery can be dangerous if you lose awareness, consciousness, or control.

  Some states have driver’s license restrictions that are dependent upon the driver’s ability to control their seizures. These states may require that an individual be seizure-free for a certain minimum amount of time—ranging from months to years—before being allowed to drive.

• Drowning: People with epilepsy are 15–19 times more likely to drown while swimming or bathing than those without the condition due to the possibility of having a seizure while in water.

• Mental health issues: People with epilepsy are at a higher risk for mental health conditions, especially anxiety, depression, and suicidal thoughts and behaviors. These problems may arise as a result of the side effects of epilepsy medications, as well as the difficulties of dealing with the disorder.

  If you or someone you know is exhibiting suicidal thoughts or behaviors, please call the National Suicide Prevention Lifeline at 1-800-273-TALK. You can also visit suicide.org to find a phone number to call in your country.

• Complications during pregnancy: Having a seizure during pregnancy can be dangerous for both the mother and baby. Certain anti-seizure medications also increase the risk of birth defects.

  That said, most women with epilepsy are able to become pregnant and give birth to healthy babies. It’s crucial that you talk to your healthcare provider if you have epilepsy and are considering becoming pregnant.

While uncommon, other life-threatening complications of epilepsy include:

• Status epilepticus: Status epilepticus is a condition that occurs when a person remains in a state of continuous seizure activity lasting for more than five minutes or has frequent, recurring seizures without regaining full consciousness between episodes. People with this condition have an increased risk of permanent brain damage and death.
• Sudden unexpected death in epilepsy (SUDEP): Roughly 1% of people with epilepsy die of SUDEP. While the cause of the condition is unknown, research has suggested that it may result from heart or respiratory conditions. People with frequent tonic-clonic seizures and those whose epilepsy isn’t controlled with medication may also be at a higher risk of SUDEP.