A febrile seizure, also called a febrile convulsion or a fit, is a seizure that happens while a young child has a fever, usually from an ordinary infection. About one child in 20 to 30 has one. Most last two or three minutes, stop on their own, and leave no lasting mark. This post goes through what causes them, the two types doctors talk about, the first aid, and when to call 999. The fever itself is covered in our fever guide.
What a febrile seizure is
When your child has an infection, their body releases chemicals that fight it, and those chemicals raise the temperature. A young child’s brain is still developing and is more easily tipped into a fit than an adult’s. In a child who is prone to them, the fever is the trigger.
It can look like this: the body goes stiff, the arms and legs jerk or twitch, the eyes roll, and your child stops responding to you. They may go red, pale or blue, and they may wet themselves or be sick. Afterwards they are usually sleepy or confused for up to an hour.
Three things about the fever surprise most parents:
- It can happen with a low fever. A seizure doesn’t need a very high temperature.
- The number doesn’t predict it. How high the fever goes is not a reliable guide to whether a seizure will come.
- It is often the first sign. Many happen in the first hours of an illness, as the temperature rises, sometimes before you knew your child was ill.
Nobody can say for certain which child will have one.
Who has them
- Age: most often between 6 months and 5 years, and sometimes up to 6. The most common age is 12 to 18 months.
- Family history: they run in families. If a parent or brother or sister had them, your child is more likely to, roughly one in five when a sibling has had one. More likely is not certain: most of those children never have one.
- Any infection, any temperature. Colds, ear and throat infections, chest infections and urine infections can all set one off.
Simple or complex
Doctors sort febrile seizures into two kinds, because the kind decides how much checking your child needs afterwards.
| Simple | Complex | |
|---|---|---|
| How long | Less than 15 minutes | 15 minutes or longer |
| Which parts | The whole body, both sides | One part or one side of the body, or sometimes the whole body |
| How often | Once, and not again within 24 hours | Again within 24 hours, or during the same illness |
| Recovery | Back to normal within a short time | May need more checks, especially if recovery is slow |
| Outlook | Excellent. No brain damage | A higher chance of epilepsy later, though most children don’t develop it |
One complex feature is enough to make a seizure complex.
Do they cause brain damage?
A simple febrile seizure does not. It doesn’t harm the brain or change how your child grows and learns. That is true even of children who have several.
A complex febrile seizure needs a closer look, and depending on how it happened and how your child recovered, a doctor may want to follow them up. It carries a higher chance of epilepsy later: about five children in a hundred, compared with barely more than any other child after a simple one. Put the other way, 95 children in 100 with a complex seizure never develop epilepsy.
About one child in three has another one with a later illness, and the younger they were the first time, the likelier that is: about one in two if the first came before their first birthday. Most children grow out of them by 5 or 6.
Fever medicine won’t prevent them. Paracetamol and ibuprofen make a feverish child more comfortable, but they don’t stop seizures, so there’s no need to give them on a schedule to ward one off. Most children need no regular medicine after a febrile seizure. A child who had a long one may be sent home with a rescue medicine and a plan for when to use it.
First aid during a seizure
- Put your child on their side when it is safe to. This keeps the airway clear and lets saliva or sick drain out of the mouth.
- Protect them from injury. Move anything hard or sharp out of the way, put something soft under their head, and stay with them.
- Don’t hold them still. Never pin them down, and never put your fingers, a spoon, medicine or anything else in their mouth. A child can’t swallow their tongue.
- Time it. Note when it starts, and watch what the arms and legs do. If someone else is there and it’s safe, a short video helps the doctor more than any description.
- Let them recover. Stay with them and watch their breathing. When the jerking stops, keep them on their side while they are drowsy or not fully awake.
What not to do. Don’t try to stop the jerking. Don’t pour water over them, put them in a bath or try to cool them quickly. Don’t give food, drink or medicine by mouth until they are fully awake. Don’t leave them alone.
When to call 999
Call 999 straight away if:
- The seizure lasts 5 minutes or longer. Don’t wait past 5 minutes to call.
- It is your child’s first seizure, even if it stops quickly. They need to be seen urgently.
- They have trouble breathing or turn blue.
- The jerking is on one side of the body only, especially if it is the first time.
- Another seizure starts before they have recovered from the first, or there is more than one in 24 hours.
- They don’t wake up, or are still unusually drowsy more than an hour afterwards.
Don’t drive your child to A&E while they are still fitting or unconscious. Call 999 instead. If a seizure was short, your child has had one before, and they are back to themselves, call your GP or NHS 111 so a doctor can find what caused the fever.
Not every fit with a fever is a febrile seizure
A child with a fever and a seizure may have an infection that needs urgent treatment, such as meningitis. Don’t assume it is a febrile seizure if your child is very unwell, or if you notice:
- A stiff neck, or bright light hurting their eyes.
- A rash that doesn’t fade when you press a glass against it.
- A bulging soft spot on a baby’s head.
- Drowsiness or confusion that doesn’t lift after the seizure.
Any of these means call 999.
Common questions
Will a febrile seizure damage my child’s brain?
A simple febrile seizure, the common kind that lasts less than 15 minutes, doesn’t cause brain damage or affect how your child develops, even if they have several. A complex seizure, one that is long, affects one side of the body or happens again within 24 hours, needs more checks, and carries a higher chance of epilepsy later, but most of those children never develop it.
Will my child have another one?
About one child in three does, with a later illness. The chance is higher if the first came before 18 months, came with a low fever, or there are febrile seizures in the family. Most children grow out of them by 5 or 6.
Does a febrile seizure mean epilepsy?
No. Epilepsy means seizures that keep happening without a fever. After a simple febrile seizure the chance of epilepsy is barely higher than for any other child. After a complex one it is about five in a hundred.
Can I stop it happening by keeping the fever down?
No. Paracetamol and ibuprofen make a feverish child more comfortable but don’t prevent febrile seizures, and cooling a child with water or fans doesn’t either. Give fever medicine for comfort, not to ward off a seizure.
Should my child still have their vaccinations?
Yes. A fever after a vaccination can occasionally bring on a febrile seizure, but the vaccines protect against illnesses that cause far higher fevers. Keep to the schedule, and talk to your GP or health visitor if you are worried.
Doodlebug keeps the record
Log each temperature and each dose in two taps, and add the seizure under Symptoms with a note: when it started, how long it lasted, what it looked like. When the doctor asks, the answer is on one timeline instead of in a frightened memory. It’s free on the App Store.
Get DoodlebugSources
- NHS, Febrile seizures.
- The Royal Children’s Hospital Melbourne, Febrile seizures and Febrile seizure (clinical practice guideline).
- Epilepsy Action, Febrile seizures.
- St George’s University Hospitals NHS Foundation Trust, Febrile convulsions: information for parents; NHS Lothian, Febrile convulsion information leaflet.
- American Academy of Pediatrics, Febrile seizures.
Doodlebug is a tracking app, not a medical service. This page is general information drawn from published guidance and is not advice about your child. Rescue medicine plans and the name of your emergency number vary by country: follow the plan your own doctor gave you. If you are worried about your child, get medical help.