A seizure happens when groups of brain cells fire abnormally and too synchronously, disrupting the brain’s normal electrical signaling. What it looks like depends on where it starts and how far it spreads, so symptoms can range from brief staring or confusion to stiffening and shaking.

What is happening in the brain

Normally, neurons send coordinated electrical and chemical signals so the brain can control movement, speech, memory, sensation, and awareness. During a seizure, that balance between excitation and inhibition breaks down, creating a burst of disorganized activity sometimes described as an “electrical storm.”

Why symptoms vary

If the abnormal activity stays in one area, the seizure may mainly affect one function, like a sensation, emotion, or a small movement. If it spreads, it can affect awareness or the whole body, which is why some people have staring spells while others have convulsions.

Common effects

  • Confusion or loss of awareness.
  • Strange sensations, smells, or emotions.
  • Stiffening or jerking movements.
  • Trouble speaking, remembering, or responding.
  • Tiredness, headache, or confusion afterward.

Brain injury risk

Most seizures do not permanently damage the brain, but prolonged or uncontrolled seizures can be harmful. Longer events and status epilepticus are the situations most associated with brain injury risk.

When to get urgent help

Seek emergency care if a seizure lasts more than 5 minutes, if another seizure starts right away, if the person has trouble breathing, is injured, or does not wake up normally afterward.

If you want, I can also explain this in a very simple 3-sentence version or break down what happens in a focal seizure versus a tonic-clonic seizure.