A grand mal seizure, now called a generalized tonic-clonic seizure, typically lasts one to three minutes. Most resolve on their own within that window. Any seizure lasting five minutes or longer is a medical emergency and requires a 911 call.
What Happens During the Seizure
A grand mal seizure has two distinct phases that happen back to back. The first is the tonic phase: every muscle in the body stiffens at once. The person loses consciousness, may cry out involuntarily (from air being forced past tightened vocal cords), and often falls to the ground. This phase is brief, generally lasting 10 to 20 seconds.
The second is the clonic phase: the muscles begin jerking rhythmically on both sides of the body. This is what most people picture when they think of a seizure. The jerking gradually slows in frequency and then stops. The clonic phase accounts for most of the seizure’s total duration, typically lasting one to two minutes. Breathing can be irregular or temporarily paused during both phases, which is why the person’s lips or face may look bluish.
The Five-Minute Rule
If a seizure reaches the five-minute mark without stopping, it crosses into a dangerous territory called status epilepticus. At that point, the brain’s normal mechanisms for shutting down a seizure are failing, and the risk of brain injury, breathing problems, and other complications rises sharply. The Neurocritical Care Society defines status epilepticus as five or more minutes of continuous seizure activity, or repeated seizures without the person returning to normal consciousness in between.
This is why the single most important thing a bystander can do is start timing the seizure. Pull out your phone and note when it started. If it hits five minutes, call 911 immediately.
Recovery Takes Longer Than the Seizure
The seizure itself may be over in a couple of minutes, but the aftermath, called the postictal state, lasts considerably longer. This recovery period typically runs 5 to 30 minutes, though it can stretch well beyond that. During this time, the person may feel confused, extremely drowsy, disoriented, or nauseated. Headaches are common. They may not remember the seizure or even the minutes leading up to it.
Some people experience effects that linger for hours or even days. Temporary weakness on one side of the body (called Todd’s paresis) can take one to two days to fully resolve, and it sometimes gets mistaken for a stroke. Mood changes, mental fog, and deep fatigue can also persist for a day or two after a particularly intense seizure. People who already have some baseline cognitive challenges tend to have longer postictal recovery periods.
What to Do if You’re With Someone Having a Seizure
Your job as a bystander is simple: keep the person safe and track time.
- Ease them to the ground if they’re standing, and move away hard or sharp objects nearby.
- Turn them on their side once the jerking stops to help keep their airway clear.
- Time the seizure from the moment it starts.
- Do not put anything in their mouth. People cannot swallow their tongues during a seizure, and objects placed in the mouth can cause injury.
- Do not try to hold them down or restrain the jerking movements.
Call 911 if the seizure lasts longer than five minutes, if the person doesn’t regain consciousness afterward, if they have trouble breathing once the seizure ends, if they’re injured, or if it’s their first known seizure. For someone with a diagnosed seizure disorder, a single seizure that stops within a few minutes and follows their usual pattern may not require an emergency call, but any seizure that looks different from their typical episodes warrants medical attention.
Why Seizures Feel Longer Than They Are
One thing nearly every witness reports: the seizure felt like it lasted forever. A two-minute seizure can feel like ten. This is completely normal and is exactly why checking a clock or phone matters so much. Your sense of time during a stressful event is unreliable, and the difference between a two-minute seizure and a five-minute seizure has real medical consequences. If emergency responders ask how long it lasted, having an actual number rather than a guess helps them make better treatment decisions.