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NeurologistCareCrystal Lake, IL · Woodstock, IL · Lake Geneva, WI

Seizures

What Happens to Your Brain During a Seizure?

A seizure is abnormal electrical activity in the brain — and it can look like much more than convulsions.

Written and medically reviewed by Amarish Dave, DO, board-certified neurologist. This page is educational and does not replace an individual medical evaluation.

Video with Amarish Dave, DO, Board-Certified Neurologist

Direct answer

Brain cells normally communicate through carefully regulated electrical and chemical signals. During an epileptic seizure, groups of neurons develop abnormal, excessive, or synchronized electrical activity, temporarily disrupting normal brain function. What a seizure looks like depends partly on where that abnormal activity begins and how it spreads — which is why a seizure can cause much more than convulsions.

Symptoms may include:

  • Staring or loss of awareness
  • Unusual sensations, or changes in emotions or perception
  • Repetitive movements
  • Muscle stiffening or jerking
  • Loss of consciousness

Because these events come from disrupted brain signaling, they deserve careful evaluation. A neurological workup — history, examination, EEG, and brain imaging — helps determine what happened, whether it is likely to recur, and how to reduce future risk.

Focal vs. Generalized Seizures

Focal seizures begin in one area of the brain and produce symptoms related to the functions controlled by that area — for example, twitching of one limb, a sudden unusual smell or taste, a rising sensation in the stomach, or a brief period of altered awareness.

Generalized seizures involve abnormal neuronal activity that rapidly emerges across both sides of the brain and may affect awareness, muscle tone, or movement — from brief absence (staring) seizures to tonic-clonic seizures with stiffening, jerking, and loss of consciousness.

Why Are You Tired or Confused After a Seizure?

The minutes to hours after a seizure are called the postictal period. The intense burst of abnormal electrical activity — and the brain's work to restore normal signaling — can temporarily leave affected networks functioning below baseline. Fatigue, deep sleepiness, confusion, headache, or difficulty speaking are common while the brain recovers. Persistent or worsening confusion, weakness, or symptoms unlike a person's usual recovery pattern should be evaluated promptly. Learn more about full evaluation and treatment on our seizures and epilepsy page, and about finding a seizure neurologist in our region.

Key takeaways

  • A seizure is abnormal, excessive, or synchronized electrical activity in the brain.
  • Symptoms depend on where the activity begins and how it spreads.
  • Seizures can cause much more than convulsions — including staring, unusual sensations, and changes in awareness.
  • Focal seizures start in one brain area; generalized seizures involve both sides rapidly.
  • Tiredness and confusion after a seizure (the postictal period) are common while the brain recovers.
  • A first-time possible seizure should always be evaluated by a medical professional.

Frequently asked questions

What happens to the brain during a seizure?
Brain cells normally communicate through carefully regulated electrical and chemical signals. During an epileptic seizure, groups of neurons develop abnormal, excessive, or synchronized electrical activity, which temporarily disrupts normal brain function in the affected areas.
Do all seizures cause convulsions?
No. A seizure can cause much more than convulsions — and many seizures involve no shaking at all. Depending on where the abnormal activity begins and spreads, symptoms can include staring, loss of awareness, unusual sensations, repetitive movements, changes in emotions or perception, muscle stiffening or jerking, or loss of consciousness.
What is a focal seizure?
A focal seizure begins in one area of the brain. It produces symptoms related to the functions controlled by that area — for example, twitching of one hand, a sudden unusual smell, a rising feeling in the stomach, or a brief period of confusion or unresponsiveness.
What is a generalized seizure?
A generalized seizure involves abnormal neuronal activity that rapidly emerges across both sides of the brain. It can affect awareness, muscle tone, or movement — ranging from brief staring (absence seizures) to stiffening and jerking with loss of consciousness (tonic-clonic seizures).
Why are you tired or confused after a seizure?
The period after a seizure is called the postictal period. The intense burst of abnormal electrical activity — and the brain's effort to restore normal signaling — can temporarily leave affected networks working below baseline, causing fatigue, sleepiness, confusion, headache, or difficulty speaking that may last minutes to hours.
What is the difference between a seizure and epilepsy?
A seizure is a single event of abnormal brain electrical activity. Epilepsy is a neurological condition in which a person has an enduring tendency to have recurrent, unprovoked seizures. Many things can provoke a one-time seizure without meaning someone has epilepsy.
How does a neurologist evaluate seizures?
Evaluation typically includes a detailed history of the events (often with a witness account), a neurological examination, an EEG to look at the brain's electrical activity, brain imaging such as MRI, and sometimes blood testing — all aimed at understanding what happened and why.
When should a possible seizure be evaluated?
Any first-time possible seizure deserves prompt medical evaluation. Seek emergency care for a seizure lasting more than five minutes, repeated seizures without recovery between them, a seizure in water, or serious injury. Otherwise, schedule a neurological evaluation promptly — diagnosis guides driving safety, treatment, and prevention.

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Concerned about a possible seizure?

In-person neurological evaluations are available in Crystal Lake and Woodstock, Illinois, and Lake Geneva, Wisconsin, with telehealth available when appropriate for patients physically located anywhere in Illinois or Wisconsin at appointment time.

Medical disclaimer

This information is for general educational purposes and is not individualized medical advice. Call 911 for a seizure lasting more than five minutes, repeated seizures without recovery between them, a seizure occurring in water, or serious injury during a seizure. Eligibility for evaluation and treatment requires an individualized medical assessment.

Schedule a Seizure Evaluation

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In-Person Neurology Visits

Available at three office locations:

Crystal Lake, Illinois
Woodstock, Illinois
Lake Geneva, Wisconsin

Telehealth Neurology Visits

Telehealth neurology appointments are available to patients located anywhere in Illinois or Wisconsin. You do not need to live near an office, but you must be physically located in Illinois or Wisconsin at the time of the appointment.

Learn about telehealth neurology →

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Illinois appointments: 815-337-7100. Wisconsin appointments: 262-245-0535.

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Insurance and referrals

Insurance participation and referral requirements vary by plan. Our office will confirm what your plan requires before your visit.

Call for an Illinois appointment: 815-337-7100Call for a Wisconsin appointment: 262-245-0535

If you believe you are experiencing a medical emergency, call 911 or seek emergency medical attention.