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There are many types of seizures. Each one causes different physical, emotional, and behavioral changes.

The most commonly known seizure causes uncontrollable shaking and jerking movements. But in other types, a person might fall down or become very still. Sometimes, it can be difficult to tell that someone is having a seizure at all.

Not all seizures are due to epilepsy, a condition characterized by recurring seizures. Some people only have one seizure in their lifetime.

Recognizing the different symptoms of seizures can help you determine the type. Read on to learn how seizures are classified, which symptoms they cause, and what to do if a seizure occurs.

Neurons, or nerve cells, send information from your brain. They do this by releasing electrical impulses in an orderly fashion.

If this electrical activity suddenly increases, it’s called a seizure. It occurs when many neurons rapidly release electrical impulses, causing uncontrollable and temporary symptoms.

Seizures are classified based on the parts of the brain involved. They include:

Focal seizures

In a focal seizure, the abnormal electrical activity starts in one area of the brain. This used to be called a partial seizure.

Focal seizures are common. Approximately 60 percent of people with epilepsy have focal seizures.

Generalized seizures

Generalized seizures start in both sides of the brain. Sometimes, a focal seizure can become generalized if it spreads.

Focal seizures occur on one side of the brain. Types include:

Focal aware seizure

During a focal aware seizure, previously called a simple focal seizure, you do not lose consciousness. You’re aware of yourself and surroundings.

Symptoms include:

  • unusual head or eye movements
  • dilated pupils
  • tightened muscles
  • numbness
  • tingling
  • sensation of crawling on the skin
  • hallucinations
  • nausea
  • sweating
  • facial flushing
  • fast heart rate
  • vision changes
  • emotional changes
  • difficulty speaking
  • sensation of déjà vu

This seizure may last between a few seconds and 2 minutes.

Focal impaired awareness seizure

A focal impaired awareness seizure happens when your consciousness is partially or completely lost. It used to be called a complex focal seizure or complex partial seizure.

You won’t be aware of yourself and surroundings, but you’ll seem awake. Possible symptoms include:

  • inability to respond
  • blank staring
  • appearance of daydreaming
  • lip smacking
  • running
  • screaming
  • crying or laughing
  • repeating words or phrases
  • performing involuntary dangerous actions, like walking into traffic
  • becoming rigid and still

This seizure typically lasts between 1 to 2 minutes. After the seizure, you may feel sleepy and confused.

Focal to bilateral tonic-clonic seizures

This seizure occurs when a focal impaired awareness seizure becomes generalized, or spreads to both sides of the brain. It used to be called a secondary generalized seizure.

It involves two phases. The first phase is called the tonic phase. It causes muscle stiffening. Other symptoms include:

  • loss of consciousness
  • falling to the floor
  • crying
  • groaning
  • biting your tongue or inside of cheek
  • difficulty breathing

The second phase is called the clonic phase. It causes jerking arm and leg movements, along with:

  • facial twitching
  • repeated flexing and relaxing of muscles
  • impaired control of the bladder or bowel

This seizure lasts between 30 seconds to 3 minutes.

Gelastic and dacrystic seizures

These seizures begin in the hypothalamus, which is located at the base of the brain.

Gelastic seizures, or laughing seizures, involve involuntary laughing. Dacrystic seizures cause involuntary crying. You don’t lose consciousness during these seizures.

There are many kinds of generalized seizures, including:

Generalized tonic-clonic seizures (GTC)

Generalized tonic-clonic seizure (GTC), previously called a grand mal seizure, begins on both sides of the brain. It’s different from a focal to bilateral tonic-clonic seizure, which starts on one side and then spreads.

It consists of two stages. The tonic phase involves:

  • muscle stiffening
  • loss of consciousness
  • falling to the floor
  • crying
  • groaning
  • biting your tongue or inside of cheek
  • difficulty breathing

The clonic phase causes:

  • rapid jerking movements
  • facial twitching
  • impaired bladder or bowel control

A GTC seizure may last 1 to 3 minutes.

Tonic seizures

A tonic seizure only causes muscle stiffening. It typically occurs during sleep and involves muscles in the:

  • back
  • legs
  • arms

Tonic seizures may cause people to fall down if they are standing or walking when the seizure occurs.

Clonic seizures

These seizures only involve repeated muscle jerking, or clonic movements.

Absence seizures

Absence seizures, previously called petit mal seizures, are often mistaken for daydreaming.

There are two types:

  • Typical absence seizure. This seizure causes sudden symptoms like blank staring and fluttering eyelids. It generally lasts less than 10 seconds.
  • Atypical absence seizure. The symptoms, which develop slowly, may include blank staring, eye blinking, hand motions, and fluttering eyelids. This seizure usually lasts 20 seconds or longer.

Myoclonic seizures

A myoclonic seizure causes sudden muscle jerking without impaired consciousness. It typically involves muscles on both sides of the body.

Generally, these seizures last for 1 or 2 seconds. They often happen multiple times within a day or several days.

Atonic seizures

In an atonic seizure, or drop attack, you suddenly lose muscle tone. Symptoms include:

  • falling from standing position
  • sudden head dropping
  • inability to respond

Infantile or epileptic spasms

An epileptic spasm involves brief extending or flexing of the arm, leg, or head. It commonly affects children younger than 2 years old. If it occurs in an infant, it’s called an infantile spasm.

These spasms last 1 to 3 seconds. They usually reoccur every few seconds over 10 minutes, which can happen several times a day.

Some disorders may cause symptoms that look like epileptic seizures. However, these disorders require different treatment and care. They include:

Febrile seizures

A febrile seizure occurs when a child between 6 months and 5 years old has a fever. It may be the first sign that a child is sick.

There are two types:

  • Simple febrile seizure. This affects the whole body and lasts less than 15 minutes. Only one seizure occurs in 24 hours.
  • Complex febrile seizure. This seizure is limited to one body part or lasts more than 15 minutes. It may happen multiple times in 24 hours.

Febrile seizures tend to run in families.

Nonepileptic events (NEE)

NEE, or pseudoseizures, are associated with extreme stress and psychological disorders. They aren’t caused by abnormal changes in the brain’s electrical activity.

These seizures most commonly affect people who have:

NEE may look like GTC seizures. But unlike GTC, they cause muscle jerking that’s out of phase and not rhythmic.

The most common seizures in babies include:

  • focal aware seizures
  • focal impaired awareness seizures
  • focal to bilateral tonic-clonic seizures
  • gelastic and dacrystic seizures
  • generalized tonic-clonic seizures
  • tonic seizures
  • clonic seizures
  • myoclonic seizures
  • atonic seizures
  • febrile seizures
  • infantile spasms

Children can have the following seizures:

  • focal aware seizures
  • focal impaired awareness seizures
  • focal to bilateral tonic-clonic seizures
  • gelastic and dacrystic seizures
  • generalized tonic-clonic seizures
  • tonic seizures
  • clonic seizures
  • absence seizures
  • myoclonic seizures
  • atonic seizures
  • febrile seizures
  • epileptic spasms
  • nonepileptic events

In adults, the most common seizures are:

  • focal aware seizures
  • focal impaired awareness seizures
  • focal to bilateral tonic-clonic seizures
  • gelastic and dacrystic seizures
  • generalized tonic-clonic seizures
  • tonic seizures
  • clonic seizures
  • absence seizures
  • myoclonic seizures
  • atonic seizures
  • nonepileptic events

Any event or condition that disrupts the brain can cause seizures. There are many possible causes.

Examples include:

Sometimes, the cause of a seizure is unknown.

Having a seizure can pose safety risks, including:

  • falls and slips
  • tongue lacerations (from biting)
  • pregnancy complications
  • drowning (while in water)
  • motor vehicle accidents (while driving)
  • anxiety
  • stress
  • depression
  • sudden unexpected death (SUDEP)

Some seizures cause symptoms just before they start. If you notice these warning signs, here’s what you should do:

  • Find a safe area without hazardous items or furniture.
  • Loosen clothing around your neck.
  • Let someone know what is happening.
  • If you’re driving, pull over.
  • If you’re near water or a heat source, like a campfire, move away.
  • Follow your seizure action plan.
  • Consider lying down or sitting.

If another person is having a seizure, try to stay calm. Keep them safe by following these steps:

  • Remove hard or sharp items from their surroundings.
  • If the person is standing, gently hold them and guide them to the floor.
  • If the person is on the floor, carefully turn them on their left side to help them breathe.
  • Remove their eyeglasses.
  • Place their head on something soft, like a folded jacket.
  • Loosen any ties, scarves, or clothing around the neck to help them breathe.
  • Don’t hold them down during the seizure.
  • Don’t put anything in their mouth.
  • Don’t offer them food or water until they’re fully awake.
  • Speak calmly as they wake up.

Note what time the seizure begins. It should last only a few minutes.

Medical emergency

If a seizure lasts longer than 3 minutes, call 911. You should also call 911 in the following scenarios:

  • This is the person’s first seizure.
  • They have another seizure right after.
  • They have difficulty breathing after the seizure.
  • They don’t wake up after the seizure.
  • They are pregnant.
  • They have a medical condition, such as diabetes or heart disease.

A seizure that lasts longer than 3 minutes warrants emergency help.

If it’s your first seizure, be sure to see a doctor. You should also consult a doctor if:

  • you continue experiencing seizures
  • the seizure was caused by an injury
  • you were injured during the seizure
  • you had a seizure while pregnant
  • you have new symptoms, like weakness or tingling

The symptoms of seizures vary by type. Some seizures cause uncontrollable jerking movements, while others cause muscle stiffening or falling. They may also involve involuntary laughing, blank staring, or hand motions.

If someone is having a seizure, clear the area and guide them slowly to the floor. Avoid holding them down or putting anything in their mouth. This will keep them safe and prevent injury. If the seizure lasts longer than 3 minutes, call 911.