Fever & Illness

Febrile Seizures: What Parents Need to Know

By Dr Soubhagya Khare10 September 20268 min read

A febrile seizure can be one of the most frightening things a parent witnesses — but understanding what's actually happening, and why it's usually not as dangerous as it looks, makes a real difference. This article is a companion to our general Seizure First Aid guide, which covers the safety steps in detail.

What a febrile seizure is

A febrile seizure is a convulsion associated with fever (a temperature of 38.0°C/100.4°F or higher), occurring in a child between about 6 months and 5 years old, with the peak age around 12–18 months, and without an infection of the brain or spinal cord itself causing it. It's the most common type of seizure triggered by fever in young children, and on its own, it is not epilepsy and does not affect a child's long-term intelligence or development. Much of the guidance below on testing and evaluation — particularly around EEG and imaging — applies specifically to children who are neurologically healthy and have had what doctors call a simple febrile seizure, a distinction explained in the next section. See our general guide on fever in children for how fever itself is usually assessed and managed.

Why it happens

It isn't fully understood why some children have febrile seizures and others don't, and the exact mechanism isn't fully worked out. What's clear is that they occur in association with fever, in a young, still-developing brain that appears to have a lower threshold for this kind of electrical disturbance during illness. It is not caused by anything a parent did or didn't do. Some children have a family history of febrile seizures — among first-degree relatives (parents and siblings) of a child with febrile seizures, roughly 10–20% may have had one too — but many children with no family history have them as well.

Simple versus complex febrile seizures

Simple febrile seizures involve the whole body, last less than 15 minutes, and don't recur within the same 24-hour period. Most febrile seizures are simple.
Complex febrile seizures last longer than 15 minutes, affect only one side of the body, or recur within the same day.

It's important to be honest about a real limitation here: you cannot reliably tell, in the moment, which type your child is having. A seizure that looks brief and straightforward can still turn out to have complex features, or the fever itself could have a more serious underlying cause. This is exactly why any first febrile seizure needs prompt medical evaluation — not because most turn out to be dangerous, but because you can't safely assume in advance that a given episode is the simple, lower-concern kind.

What to do during the seizure

The safety steps are the same as for any seizure: stay calm, time it, ease your child to the ground, clear the area, turn them onto their side once safely down, and don't put anything in their mouth or give anything by mouth. See our full Seizure First Aid guide for the complete list of what to do and what to avoid.

Same-day medical assessment versus a genuine emergency

These aren't quite the same thing, and it's worth telling them apart.

Your child's first-ever febrile seizure always needs medical assessment on the same day — even if it was brief and your child looks completely recovered, and even if none of the emergency signs below are present. This is routine, important assessment to identify the cause of the fever and check for anything else concerning, not necessarily a 911-level emergency in itself. Many families do go straight to an emergency department or urgent care for a first seizure simply because it's the fastest way to be seen, and that's a reasonable choice — but the underlying reason is "this needs prompt assessment," not automatically "this is a life-threatening emergency."

Call for emergency medical help immediately if:

The seizure lasts longer than 5 minutes
Your child has a second seizure before fully recovering from the first
Your child has difficulty breathing during or after the seizure
Your child is injured during the seizure
Your child shows persistent difficulty waking, abnormal responsiveness, or does not return toward their usual level of alertness within a reasonable time after the seizure ends

Also arrange prompt medical assessment (same day, even if the seizure has already stopped and your child seems otherwise well) if:

The seizure had complex features — one-sided (focal) movements, or more than one seizure within the same day
Your child is younger than 6 months or older than 5 years — a "febrile seizure" outside the typical age range needs fuller evaluation, since the diagnosis is less certain
There are signs suggesting a more serious infection rather than a simple febrile seizure — such as a stiff neck, a rash that doesn't fade under pressure, or a child who remains extremely unwell even after the seizure itself has resolved

Do we need an MRI or EEG?

This depends on the type of seizure, so it's worth being specific about scope. Current pediatric guidance on skipping routine testing applies to neurologically healthy children between 6 and 60 months old who have had a simple febrile seizure. For these children, an EEG, brain imaging (MRI/CT), or blood tests are generally not needed solely because of the seizure itself, even if they've had more than one — the focus of evaluation is on identifying the source of the fever and checking for clinical features that might suggest meningitis or another serious illness, not on imaging the brain as a routine step.

This guidance does not mean these tests are never useful after a febrile seizure. For a child with a complex febrile seizure, an abnormal neurological exam, an unusually ill appearance, or other concerning features, further testing — which may include an EEG or imaging — is considered individually by your child's doctor based on the specific clinical picture.

Recurrence

Roughly 30–40% of children who have one febrile seizure will have at least one more. The chance of recurrence is higher in children who:

Had their first febrile seizure before 12 months of age (recurrence risk up to around 50%, compared to about 30% for children older than 12 months at onset)
Had a relatively short fever (under an hour) before the seizure occurred
Have a first-degree relative who has had febrile seizures

Why fever-reducing medicine doesn't prevent seizures

This is worth stating clearly: giving paracetamol or ibuprofen at the first sign of fever does not reliably prevent a febrile seizure. These medicines can help with your child's comfort, but multiple studies have not shown a consistent benefit in preventing febrile seizures themselves, and current guidance does not recommend relying on them for that purpose. Treat fever for your child's comfort, not as seizure prevention.

Long-term outlook

Most children outgrow febrile seizures by around age 5, and studies have found that even children with multiple episodes have intelligence and school performance comparable to children who never had one. The risk of later developing epilepsy after a simple febrile seizure is similar to the general population's baseline risk — around 1%, compared to roughly 0.5–1% in children generally. The risk is higher for children whose febrile seizures had complex features, and your doctor may discuss closer, individualized follow-up in that situation.

Febrile seizures are not epilepsy

This distinction matters. A febrile seizure is provoked specifically by fever and, in its simple form, doesn't usually need ongoing anticonvulsant medication. Epilepsy involves recurring seizures that are not triggered by fever. A small number of children with febrile seizures — particularly those with complex features, a family history of epilepsy (rather than just febrile seizures), or an existing developmental delay — do have a higher chance of later epilepsy, which is why these factors are specifically asked about during evaluation.

Frequently asked questions

Will my child need daily medication to prevent future febrile seizures? Usually not. Simple febrile seizures, even if they happen more than once, generally don't need ongoing anticonvulsant medication. Your doctor may discuss other options individually if your child has frequent or complex episodes.

Does a febrile seizure mean my child has epilepsy? No. A febrile seizure on its own is not epilepsy, and most children who have one never go on to develop epilepsy.

Should I give fever medicine right away to stop another seizure from happening? Fever medicine can help your child feel more comfortable, but it will not reliably prevent another febrile seizure. Give it for comfort, and follow the seizure safety steps if another seizure does occur.

See our Childhood Fever and Acute Illness service page for more on how fever is evaluated at this clinic.