Seizures can be frightening and overwhelming, not just for someone having a seizure but for their loved ones and people trying to offer help. Some seizures can be mild with barely-noticeable symptoms, while others can be complex medical emergencies requiring immediate care.

In this article, Ability Central breaks down the basics of a seizure, answering questions like:  

• What is a seizure?
• What is a focal seizure?
• What is a generalized seizure? 
• What are the stages of a seizure?
• What causes seizures?
• What is a seizure trigger?
• Are seizures dangerous? 
• How do I help someone who has a seizure?
• When should I seek medical help for a seizure? 
• Where can I get more information about seizures?

What is a seizure?

A seizure is an unexpected, uncontrollable flurry of electrical activity in the brain. This can lead to symptoms like twitching or jerking, muscle contraction, staring, and loss of consciousness. 

Most seizures last between 30 seconds and 2 minutes. Any seizure that lasts longer than 5 minutes is considered a medical emergency. While many seizures have mild symptoms and go away quickly, others can be extremely dangerous, especially if someone has a seizure in an unsafe environment, like while driving or swimming.

As many as 1 in 10 people will have at least one seizure at some point in their lives. Someone who has two or more seizures at least 24 hours apart can be diagnosed with epilepsy, a neurological disease that causes recurrent seizures. 

There are two main types of seizure: focal seizures and generalized seizures. 

What is a focal seizure?

A focal seizure results from electrical activity in one part of the brain and does not always cause someone to lose awareness or consciousness.

A focal seizure without impaired awareness changes someone’s emotions and the way they perceive the world around them. Someone having a focal seizure without impaired awareness might:

• Suddenly feel emotions that don’t match their situation, like unexplained joy, grief, or anger.
• Struggle to speak.
• Feel nauseous or dizzy.
• Involuntarily jerk a body part like an arm or a leg. 
• See flashing lights or “floaters.”
• Feel tingling or “pins and needles.” 

Meanwhile, a focal seizure with impaired awareness can temporarily make someone lose consciousness or awareness. Someone having a focal seizure with impaired awareness might: 

• Feel like they’re in a dream. 
• Seem awake, but stare into space or not respond.
• Perform repetitive movements like opening and closing their hand, pacing, or repeating a word or phrase. 
• Not remember a seizure or even know it happened. 

Because focal seizures are often mild and short, these symptoms can easily be mistaken for other conditions like migraines, mood swings, mental illness, or narcolepsy. 

What is a generalized seizure?

A generalized seizure starts in or involves all parts of the brain. Generalized seizures can be mild or severe and exhibit a variety of symptoms. Generalized seizure types include:

• Absence seizures. Similar to a focal seizure, someone having an absence seizure (formerly called a petit mal seizure) stares into space, freezes up, or makes subtle body movements, usually for 5 to 10 seconds. Most common in children, absence seizures can happen in clusters and up to hundreds of times a day. 
• Tonic seizures. A tonic seizure causes muscles to stiffen, typically in the back, arms, and legs. This type of seizure can make someone fall or lose consciousness. 
• Atonic seizures. Also called drop seizures, atonic seizures cause a loss of muscle control. Someone having an atonic seizure may drop what they’re holding or fall.
• Clonic seizures. Clonic seizures cause the repeated twitching and jerking most commonly associated with epilepsy, and usually affect the neck, arms, and face. 
• Myoclonic seizures. Similar to clonic seizures, myoclonic seizures cause jerking and twitching in the arms and legs, but usually without a loss of consciousness.
• Tonic-clonic seizures. Formerly called grand mal seizures, tonic-clonic seizures cause both body stiffening and shaking. Someone having a tonic-clonic seizure usually loses consciousness and can potentially lose control of their bladder or bite their tongue. A tonic-clonic seizure can start as a focal seizure or mild generalized seizure, then spread to affect the whole body.

What are the stages of a seizure?

Seizures occur in three stages: prodrome, ictal, and postictal. 

Prodrome is a warning of a seizure, not the seizure itself. In the prodrome stage, hours or days before a seizure, some people show behavioral changes or tough-to-explain feelings that they are about to have a seizure. Someone in the prodrome stage may also experience an aura, a strange feeling or hallucination that marks the first symptom of a seizure. Epilepsy aura symptoms include:

• Headaches.
• Numbness or tingling.
• Nausea or dizziness.
• Unexplainable feelings, like fear, anxiety, joy, or excitedness.
• Hallucinations like smells, sounds, and tastes.
• Blurred vision.
• Racing thoughts.

The ictal phase covers the seizure itself, from the first symptoms to the end of the seizure. Ictal phase symptoms depend on the type of seizure.

Finally, the postictal phase, the recovery time after a seizure, can last for minutes or hours. Some people take hours to recover from a seizure, while others feel fine after only a few minutes. Postictal phase symptoms include:

• Memory problems, especially the time right before and during the seizure.
• Fatigue, sleepiness, or weakness.
• Confusion.
• Sadness, fear, or frustration. 
• Nausea.
• Headaches.
• Thirst.
• Loss of bladder control. 

What causes seizures?

The most common cause of seizures is epilepsy, a neurological condition that alters the brain and makes people more likely to have seizures. Someone with epilepsy has at least two seizures at least 24 hours apart that have no outside cause. 

To learn more about epilepsy, see What is Epilepsy? Common Questions, Causes, and Treatments.

Not all seizures are caused by epilepsy. A seizure occurs whenever something disrupts the neural pathways in our brains, the messages sent and received by nerve cells called neurons. 

Seizures unrelated to epilepsy can be caused by:

• Brain infections, like meningitis or encephalitis. 
• Severe illnesses, like COVID-19 or RSV.
• High fevers.
• Lack of sleep.
• Certain medications, like some antidepressants, painkillers, or medications used to help people quit smoking. 
• Brain injuries, particularly head trauma. 
• Stroke.
• Low blood sodium.
• Substance abuse, particularly drugs like cocaine or amphetamines. 
• Alcohol abuse, particularly during withdrawal or extreme intoxication. 

What is a seizure trigger?

A trigger is an event or environment that makes someone more likely to have a seizure. Seizure triggers do not cause seizures themselves, but they do provoke seizures in someone who already has an epilepsy disorder. 

Common seizure triggers include:

• Missing medications.
• Stress.
• Alcohol.
• Drugs, particularly cocaine and amphetamines like Ecstasy. 
• Flashing lights.
• Exhaustion or poor sleep. 
• Poor nutrition, low blood sugar, or dehydration.
• Weather changes. 
• Menstruation.
• Illness or infection. 
• Certain smells, foods, or sensations. 
• In very rare cases, internal stimuli like strong emotions or certain thought processes. This is called a reflex seizure, in which the body “reflexively” reacts to stimuli by having a seizure. 

Are seizures dangerous?

Most seizures are not a medical emergency and will stop on their own. However, seizures can be dangerous if they happen in the wrong environment. 

The most dangerous complications of a seizure are:

• Falls that cause broken bones or head injuries.
• Drowning, if someone has a seizure while swimming or bathing.
• Car accidents, if someone has a seizure while driving. 
• Mental health complications, both as a side effect of medication and from the pressures of living with seizures. 
• Pregnancy complications. Seizures during pregnancy can be dangerous for both the baby and the person who is pregnant. In addition, some anti-epileptic medications increase the risk of birth defects.
• Sudden unexplained death in epilepsy (SUDEP). Around 1 in 1,000 people with epilepsy die unexpectedly during a seizure, unrelated to injury or drowning. Doctors don’t know why this happens, but research suggests breathing difficulties or irregular heart rhythm may be part of the cause. 

How can I help someone who has a seizure? 

The best ways to help someone having a seizure are to:

• Keep an eye on them. If a seizure puts someone in a dreamlike state, they might wander toward stairs or traffic without noticing. Gently guide them away from danger and stay nearby until the seizure subsides.
• Clear the area of sharp or hard objects.
• Give them space and keep others out of the way. 
• Do not hold them down, try to stop their movements, or put anything in their mouth. Contrary to popular myth, people cannot swallow their tongues during a seizure, but they can damage their teeth or accidentally bite people trying to help.
• Roll the person onto their side to keep airways clear. 
• Time the seizure with your watch or cell phone.
• Report seizure symptoms. Many people who have seizures either don’t remember or don’t know that they had a seizure after the fact. Keeping note of someone’s symptoms before, during, and after a seizure can help them work on treatment with their care team. 

When should I seek medical help for a seizure?

Call an ambulance or seek immediate medical attention if the person having a seizure:

• Shows seizure symptoms for longer than five minutes.
• Is pregnant.
• Doesn’t regain consciousness.
• Stops breathing. 
• Immediately has another seizure.
• Has a fever. 
• Has diabetes.
• Injured themselves during the seizure.
• Had the seizure despite taking anti-seizure medication. 
• Has had a seizure for the first time. 

Where can I get more information about seizures? 

To learn more about seizures and epilepsy, see:

• Epilepsy First Steps: What Should I Do if I Have a Seizure?
• Epilepsy: Symptoms, Types, and Stages of Seizure Disorders
• What Does Long-term Life Look Like With Epilepsy?
• What is Epilepsy? Common Questions, Causes, and Treatments

To learn more about diseases, disorders, and neurological conditions linked to seizures, see: 

• Attention-deficit/hyperactivity disorder (ADHD)
• Alzheimer's disease
• Amyotrophic lateral sclerosis (ALS)
• Apraxia and dyspraxia
• Autism
• Cerebral palsy
• Multiple sclerosis (MS) 
• Stroke