Febrile seizures

A febrile seizure is a fit that can happen when a child has a fever.

Febrile seizures are also sometimes called febrile convulsions. They are relatively common and, in most cases, aren’t serious.

Around one in 20 children will have at least one febrile seizure at some point. They most often occur between the ages of six months and three years.

During a febrile seizure, the child’s body usually becomes stiff, they lose consciousness and their arms and legs twitch. Some children may wet themselves. This is known as a tonic clonic seizure.

Read more about the symptoms of febrile seizures

Symptoms

The main symptom of a febrile seizure is a fit that occurs while a child has a fever.

Febrile seizures often occur during the first day of a fever, which is defined as a high temperature of 38C (100.4F) or above. 

However, there appears to be no connection between the extent of your child’s fever and the start of a seizure. Seizures can occur even if your child has a mild fever.

Simple febrile seizures can happen when there’s a rapid rise in temperature and you may only realise your child is ill when they have a fit. Alternatively, they can occur as your child’s temperature drops from a high level.

During simple febrile seizures:

your child’s body will become stiff and their arms and legs will begin to twitch they’ll lose consciousness and they may wet or soil themselves they may also vomit and foam at the mouth and their eyes may roll back the seizure usually lasts for less than five minutes following the seizure, your child may be sleepy for up to an hour afterwards

Complex febrile seizures tend to last longer than 15 minutes, and the symptoms may only affect one area of your child’s body. The seizure sometimes recurs within 24 hours or during the period in which your child is ill.