Types of Seizures: The Simple Guide for 2026

27 Feb 2026

Epilepsy is often talked about as if it’s one single thing. In reality, “seizure” is an umbrella term, and the type of seizure someone has can change what it looks like, how long it lasts, and what kind of support is most helpful.

In this article, we’ll walk through the main seizure types.You’ll learn the most common categories (like focal and generalised seizures), what people may experience during each one, and the signs caregivers often notice first. We’ll also cover quick “at-a-glance” differences, when to seek urgent help and why getting the seizure type right matters for treatment and safety planning.

Quick Answer

There are two main types of seizures: focal (starting in one area of the brain) and generalized (affecting both sides at once). The most recognised type — tonic-clonic — is a generalised seizure involving stiffening and rhythmic jerking. Knowing the type matters because it shapes diagnosis, treatment, and how you prepare to keep someone safe.

What are the two main types of seizures?
What is a focal seizure and what does it look like?
What is a generalized seizure and what does it look like?
What is a tonic-clonic seizure specifically?
Why do so many tonic-clonic seizures happen at night?
Focal vs Generalized: side-by-side comparison
Seizure type checklist: what to observe and report to your doctor
FAQ

What Are the Two Main Types of Seizures? {#two-types}

Seizures are classified by where they start in the brain. According to the International League Against Epilepsy (ILAE), the updated 2025 classification maintains four main classes: Focal, Generalized, Unknown, and Unclassified. But for most families and caregivers, the key distinction is the first two.

Think of the brain as two hemispheres working in constant coordination. A focal seizure ignites in one specific area or network on one side. A generalized seizure involves networks on both sides simultaneously from the very beginning. That single difference (where it starts) changes almost everything about how a seizure looks, how long it lasts, and how it's treated.

This is why the old terms "grand mal" and "petit mal," while still heard in everyday conversation, have been formally replaced. They were too vague. Modern classification, rooted in CDC epilepsy guidelines and ILAE research, gives clinicians and families a shared, precise language.

What Is a Focal Seizure and What Does It Look Like? {#focal}

A focal onset seizure, formerly called a partial seizure, begins in one side of the brain. According to the Epilepsy Society UK, focal seizures may affect a large part of one hemisphere or just a small area within a single lobe.

Focal seizures are further described by whether the person remains aware or has impaired awareness during the event:

Focal aware seizure (previously called simple partial): The person is conscious throughout. They may notice tingling, a strange smell, a déjà vu feeling, or twitching in one hand. They'll usually remember the episode. These often serve as a warning (sometimes called an aura) before a larger seizure follows.

Focal impaired awareness seizure (previously called complex partial): Awareness is affected. The person may stare blankly, make repetitive movements (picking at clothes, lip-smacking), and appear confused. They usually cannot respond normally for a few minutes and may have no memory of the event afterwards.

Focal to bilateral tonic-clonic seizure: A focal seizure that spreads to involve both sides of the brain, producing the full tonic-clonic pattern. This used to be called a "secondary generalised seizure."

Focal seizures can be hard to recognise. A child who goes still and stares briefly, or an adult who suddenly can't speak for 30 seconds, may be having one. If you're unsure, that uncertainty itself is something worth documenting and discussing with a neurologist.

What Is a Generalized Seizure and What Does It Look Like?

Generalized onset seizures begin in networks on both sides of the brain at the same time. Because they affect both hemispheres from the outset, they almost always involve some change in consciousness.

The Epilepsy Foundation outlines several key subtypes:

Tonic-clonic seizures (the "grand mal"): Stiffening followed by rhythmic jerking. The most recognised seizure type, and the most physically alarming to witness.

Absence seizures (the "petit mal"): Brief, sudden lapses in awareness, often just a few seconds. The person may stare into space and then continue as if nothing happened. Common in children.

Atonic seizures: Sudden loss of muscle tone. The person goes limp and may fall suddenly, often called "drop attacks."

Tonic seizures: Muscles stiffen without the rhythmic jerking phase.

Myoclonic seizures: Brief, shock-like jerks of a muscle or group of muscles, often in the arms or upper body.

Clonic seizures: Rhythmic jerking movements without the preceding tonic phase.

Each of these has different implications for safety, treatment, and daily life, which is exactly why getting an accurate classification from your epilepsy team matters.

What Is a Tonic-Clonic Seizure Specifically?

The tonic-clonic seizure is the type most people picture when they hear the word "seizure." It unfolds in two distinct phases, as described by the Epilepsy Foundation:

Tonic phase: All muscles stiffen. The person loses consciousness and falls if standing. Air forced past the vocal cords may produce a cry or groan. This phase usually lasts under a minute.

Clonic phase: Arms, and usually legs, begin jerking rhythmically, bending and relaxing repeatedly. After a few minutes, the jerking slows and stops.

After the seizure, the person will typically be exhausted, confused and disoriented, sometimes for minutes, sometimes for over an hour. This is called the postictal phase. They may not remember what happened at all.

Tonic-clonic seizures generally last 1 to 3 minutes. If a seizure lasts more than 5 minutes, call emergency services immediately. This is a potential medical emergency called status epilepticus.

A tonic-clonic seizure can be either generalised (starting in both sides of the brain) or focal to bilateral (starting in one area and spreading). The difference matters for treatment but doesn't change first aid in the moment.

📋 Looking for what to do during a seizure? Read our Seizure First Aid Guide for a step-by-step breakdown, including what NOT to do.

Why Do So Many Tonic-Clonic Seizures Happen at Night? {#night}

This is something many families discover the hard way: epilepsy and sleep are deeply intertwined.

Research published in PMC shows that approximately 20% of people with epilepsy experience seizures exclusively during sleep, and among those with generalised tonic-clonic seizures specifically, nocturnal occurrence is very common. A large prospective study found that 85% of patients with pure sleep epilepsy had generalised tonic-clonic seizures, with the majority occurring between midnight and 9am.

According to Epilepsy Action UK, between 10 and 15 out of every 100 people with epilepsy have sleep-related epilepsy. Certain epilepsy syndromes, including juvenile myoclonic epilepsy and epilepsy with generalised tonic-clonic seizures, have a particularly strong tendency to produce seizures during sleep or on waking.

The danger? Many nocturnal seizures go completely unwitnessed. The person may wake up with a bitten tongue, sore muscles, or overwhelming fatigue, and never know a seizure occurred. Over time, these undetected events can disrupt medication reviews, increase SUDEP risk, and leave families operating on incomplete information.

This is where monitoring becomes not just helpful, but genuinely important. Knowing that a seizure happened, even when no one was awake to see it, changes what your neurologist can do.

Lampsy: Monitoring Built for Real Nights

Lampsy is an epilepsy monitoring device designed for exactly this challenge. It detects movements that may indicate tonic-clonic seizures with over 99% accuracy, without sensors on the skin, and without looking like medical equipment in your home.

Lampsy is seamlessly embedded into a bedside lamp, so it blends into the bedroom naturally. It uses a small camera with privacy-preserving technology to track movements that may be indicative of seizures, so you get the safety of monitoring without the discomfort of surveillance. It's built on a simple principle: support, not surveillance. Independence, not intrusion.

Over 5,000 families across Europe and the UK are already on the waiting list. If night-time seizures are part of your reality, or you're simply not sure, Lampsy is worth knowing about.

Join the Lampsy waiting list and be among the first to access it →

Focal vs Generalized: Side-by-Side Comparison

	Focal Seizure	Generalized Seizure
Brain involvement	One area or one hemisphere	Both hemispheres from onset
Consciousness	May be preserved (aware) or impaired	Almost always impaired
Duration	Seconds to 2 minutes typically	Seconds (absence) to 1–3 min (tonic-clonic)
Memory of event	Often yes (if aware)	Usually no
Motor symptoms	May affect one side of body	Affects both sides
Examples	Focal aware, focal impaired awareness	Tonic-clonic, absence, atonic, myoclonic
Can it spread?	Yes, can become focal to bilateral	N/A, starts bilaterally
Old terminology	Simple/complex partial	Grand mal, petit mal

Seizure Type Checklist: What to Observe and Report to Your Doctor

Whether you're a person with epilepsy or a caregiver, what you observe and document can directly influence diagnosis and treatment. Here's what to track every time a seizure occurs:

Before the seizure:

[ ] Was there a warning (aura)? What did it feel like? (Smell, taste, déjà vu, tingling, visual change?)
[ ] What was the person doing when it started?
[ ] Time of day: particularly, was it during sleep?
[ ] Any known triggers in the hours before? (Poor sleep, missed medication, stress, alcohol)

During the seizure:

[ ] What time did it start? (Note it immediately, duration matters)
[ ] Where did movement begin? One side of the body, or both simultaneously?
[ ] Was the person responsive? Could they speak or answer questions?
[ ] Did their eyes deviate in a particular direction?
[ ] Was there stiffening, jerking, or both? In what sequence?
[ ] Did they fall? Did they lose bladder or bowel control?
[ ] Any colour change in the face (pallor, blueness)?

After the seizure:

[ ] How long until they were fully alert?
[ ] Did they have a headache, confusion, muscle soreness?
[ ] Did they remember what happened?
[ ] Total duration of the seizure

If possible: Video is extremely valuable for neurologists. A 30-second clip of a seizure can provide diagnostic information that a verbal description cannot.

📋 Also useful: Our Seizure First Aid Steps guide walks you through exactly what to do in the moment, including what NOT to do (no, you should not put anything in the person's mouth).

FAQ

What is the difference between focal and generalized seizures? A focal seizure starts in one side of the brain and may or may not affect consciousness. A generalised seizure involves both sides of the brain from the beginning and almost always affects consciousness. The distinction determines treatment approach and safety planning.

What does a tonic-clonic seizure look like? The person loses consciousness, their muscles stiffen (tonic phase), and then their arms and legs begin jerking rhythmically (clonic phase). The seizure typically lasts 1 to 3 minutes. Afterwards, the person will be confused and exhausted, and may not remember the event. If it lasts more than 5 minutes, call emergency services.

Can a focal seizure turn into a generalized seizure? Yes. A focal seizure can spread to involve both hemispheres, and this is called a focal to bilateral tonic-clonic seizure. It used to be called a "secondary generalised seizure." This is one reason why early, unwitnessed focal seizures can go unrecognised: by the time someone notices, it has already become a full tonic-clonic seizure.

What are the most common types of seizures in adults? Focal seizures are actually the most common type of epileptic seizure overall. Among generalised seizures, tonic-clonic and absence are the most frequently seen. The type can vary significantly depending on the underlying epilepsy syndrome.

What are the most common types of seizures in children? Children commonly experience absence seizures (brief staring spells), tonic-clonic seizures, and myoclonic seizures. Some epilepsy syndromes are specific to childhood, such as childhood absence epilepsy and juvenile myoclonic epilepsy. Some children outgrow their epilepsy; others do not.

Can seizures happen only at night? Yes. Between 10 and 15 out of every 100 people with epilepsy have sleep-related epilepsy, where seizures occur predominantly or exclusively during sleep. Tonic-clonic seizures are particularly common at night. Because they may go unwitnessed and are often underdiagnosed, making monitoring an important part of care for many families.

What is the difference between an absence seizure and a focal seizure? An absence seizure is generalised, it affects both sides of the brain, and typically causes a brief, blank stare with no memory of the event. A focal aware seizure may also appear as a brief "spacing out" but the person remains conscious and may recall the episode. A neurologist can distinguish these through EEG.

What should I do if I don't know what type of seizure someone is having? Focus on safety, not classification. Move dangerous objects away, time the seizure, stay calm, and place them on their side if they're unresponsive. Never restrain them or put anything in their mouth. Call emergency services if the seizure lasts more than 5 minutes. Then document everything you observed: type, duration, body movements, recovery time, to share with a neurologist.