An Overview of Seizures

Symptoms, causes, diagnosis, treatment, and coping

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When people hear the word seizure, they usually imagine someone who has collapsed and is in the throes of painful convulsions. While it's true that some having a seizure will experience these symptoms, that's not always the case. It's also a common misconception that having a seizure means someone has epilepsy. While seizures may indicate an epilepsy disorder, they can also be caused by myriad other things.

If you (or someone you know) suddenly has a seizure but has never had one before, it's important to get medical help right away. Your doctor will need to figure out what caused the seizure and whether you're likely to have more, and then begin exploring what treatment, if any, is necessary.

Categories of Seizure

Broadly speaking, there are three categories of seizures:

  • Generalized onset seizures: These affect both sides of the brain at once and can include tonic-clonic, absence, and atonic seizures.
  • Focal onset awareness seizures: This type typically affects one side of the brain; the person remains fully awake and aware.
  • Focal onset impaired awareness seizures: These also affect one side of the brain, but can causes gaps in consciousness.

Each of these categories includes several types of seizures. While someone with epilepsy may experience only one type of seizure, others may be affected by several. In those cases, the person may require different forms of treatment to control the different types of seizures.


Symptoms of seizure and their intensities vary greatly depending on the category and type. Some forms are very apparent, while others may occur without you even knowing what's going on.

  • A classic tonic-clonic seizure is the type most people recognize. Formerly called a grand mal seizure, the person's entire body goes stiff and does a lot of jerking.
  • By contrast, an absence seizure may cause a person to suddenly "blank out" for a moment, then return to full consciousness. (These used to be referred to as petit mal seizures.)
  • With atonic seizure, a body part suddenly goes limp or the head drops for several seconds.

Other types of seizures may cause a single body part to twitch violently or perhaps just jerk once or twice. Some seizure events, such as tonic-clonic, are actually combinations of two seizure types, with one type leading to the other.

Pre-Seizure Symptoms

Some people who get recurrent seizures can feel them coming on, while others don't have any pre-seizure symptoms at all.

Warning signs, should they occur, can include:

  • Suddenly feeling anxious or fearful
  • Nausea
  • Blurry vision
  • Dizziness
  • Headache
  • Aura: A visual or auditory phenomenon similar to that experienced by some people who get migraines

During the Seizure

Once the seizure itself begins, the following symptoms are possible (again, depending on category and type):

  • Blacking out
  • Blank stare
  • Sudden, rapid eye movements
  • Loss of bodily control and uncontrollable muscle jerks
  • Violent shaking
  • Collapsing
  • Drooling or frothing at the mouth
  • Vomiting
  • Clenching teeth
  • Making unusual noises
  • Loss of bladder or bowel control

If the person loses consciousness or awareness, they may wake up confused and groggy.

Often, symptoms persist for a few hours or even days after a seizure. The longer and more intense the seizure, the longer recovery tends to take.


Some seizures are caused by epilepsy, and many people believe that seizures and epilepsy are one and the same. That's not the case.

A seizure, by definition, is a transient event caused by excessive or non-synchronous brain activity. Epilepsy, by contrast, is a medical condition characterized by the recurrence of seizures. As such, a seizure is a symptom of epilepsy.

Non-epileptic seizures are a symptom of many other conditions, including:

  • Vitamin B1, B6, and B12 deficiency
  • Head injury
  • Hypoglycemia
  • Sleep deprivation
  • Brain tumor
  • Encephalitis or meningitis
  • Cerebral palsy
  • Multiple sclerosis
  • Malnutrition
  • Pharmaceutical drugs such as corticosteroids, estrogen, lidocaine, propofol, and insulin (when used incorrectly or in excess)
  • Recreational drugs, including MDMA, methamphetamines, and cocaine
  • Drug withdrawal

Around one in every 20 people living to the age of 80 will have a seizure. Anyone, at any age, can have one—even infants. In fact, babies are especially vulnerable to seizures when faced with otherwise uncomplicated abnormalities such as a fever (pyrexia) or drinking too much water (that latter of which flushes too much sodium from the body and disrupts brain activity).

On the flip side, seizures are a common feature of aging-related neurodegenerative disorders like Alzheimer’s disease.

Among older adults who have had a stroke, around 10 percent with a hemorrhagic stroke (a brain bleed) and 8 percent with an ischemic stroke (involving a blocked blood vessel) will experience one or more seizures.


If you have a seizure, your doctor will likely order a variety of tests and scans to figure out why. These may include:

You should also expect a physical and neurological exam. Try to be prepared to give a detailed medical and family history as well. Be as detailed as you can when it comes to sharing any details about your seizure(s).


More than 25 anti-seizure drugs are approved by the U.S. Food and Drug Administration (FDA). Research suggests that 70 percent of people with epilepsy can have their seizures completely controlled by using one or more of these medications. Other epilepsy treatment options involve surgeries, implants, and a strict ketogenic diet.

However, if you have a seizure that's caused by something other than epilepsy, you likely won't need an anti-seizure drug or other seizure-related treatment. Instead, your doctor will focus on the underlying cause, whether it be a fever, an electrolyte imbalance, abnormal blood sugar, a drug-related event, or a chronic illness.

An exception is brain cancer. The disease itself and brain surgery to remove tumors can lead to recurrent seizures, which may require anti-seizure drugs to control.


If your doctor believes your seizure was an isolated event, you may still worry about having another one. If you need help dealing with that fear, you may benefit from mental health counseling. Otherwise, you shouldn't need to make changes to your life based on having a single seizure.

If you're diagnosed with epilepsy or something else that may cause recurrent seizures, you may need to make some lifestyle changes and learn to cope with your diagnosis. Taking measures to ensure your safety when you have a seizure is also beneficial.

A Word From Verywell

The important thing to remember in case you or someone you know has a seizure is that it's a serious medical event that requires emergency care. However, seizures are common and doctors and nurses know how to deal with them, both in an emergency setting and if you require short-term or long-term treatment.

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