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.

What to do during a seizure

If your child is having a febrile seizure, place them in the recovery position. Lay them on their side, on a soft surface, with their face turned to one side. This will stop them swallowing any vomit, keep their airway open and help prevent injury.

Stay with your child and try to make a note of how long the seizure lasts.

If it's your child's first seizure, or it lasts longer than five minutes, take them to the nearest hospital as soon as possible, or dial 999 for an ambulance. While it's unlikely that there's anything seriously wrong, it's best to be sure.

If your child has had febrile seizures before and the seizure lasts for less than five minutes, phone your GP or NHS 111 for advice.

Don't put anything, including medication, in your child’s mouth during a seizure because there's a slight chance that they might bite their tongue.

Almost all children make a complete recovery after having a febrile seizure, and there's not a single reported case of a child dying as a direct result.

Types of febrile seizure

There are two main types of febrile seizure.

Simple febrile seizure

A simple febrile seizure is the most common type of febrile seizure, accounting for about eight out of 10 cases. It's a fit that:

is a tonic clonic seizure (see above)
lasts less than 15 minutes
doesn't reoccur within 24 hours or the period in which your child has an illness

Complex febrile seizure

Complex febrile seizures are less common, accounting for two out of 10 cases. A complex febrile seizure is any seizure that has one or more of the following features:

the seizure lasts longer than 15 minutes
your child only has symptoms in one part of their body (this is known as a partial or focal seizure)
your child has another seizure within 24 hours of the first seizure, or during the same period of illness
your child doesn't fully recover from the seizure within one hour

Why febrile seizures occur

The cause of febrile seizures is unknown, although they're linked to the start of a fever (a high temperature of 38C (100.4F) or above).

In most cases, a high temperature is caused by an infection such as:

There may also be a genetic link to febrile seizures because the chances of having a seizure are increased if a close family member has a history of them. Around one in four children affected by febrile seizures has a family history of the condition.

Read more about the causes of febrile seizures.

Complications

Febrile seizures have been linked to an increased risk of epilepsy (see below), as well as other problems.

Recent research findings may indicate a link between febrile seizures and sudden unexplained death in childhood (SUDC), possibly due to the connection between febrile seizures and epilepsy.

However, this link hasn't been proven and SUDC is incredibly rare, affecting around one in 100,000 children which is equivalent to a 0.001% chance.

In addition, one of the biggest studies of its kind looked at more than 1.5 million children with a history of febrile seizures and found no evidence of an increased risk of death in later childhood or adulthood.

Febrile seizures and epilepsy

Many parents worry that if their child has one or more febrile seizures, they'll develop epilepsy when they get older. Epilepsy is a condition where a person has repeated seizures without fever.

While it's true that children who have a history of febrile seizures have an increased risk of developing epilepsy, it should be stressed that the risk is still small.

It's estimated that children with a history of simple febrile seizures have a one in 50 chance of developing epilepsy in later life. Children with a history of complex febrile seizures have a one in 20 chance of developing epilepsy in later life.

This is compared to around a one in 100 chance for people who haven't had febrile seizures.