A febrile seizure is a fit that occurs when a child has a fever. It's a relatively common childhood condition and not serious in most cases.
Febrile seizures are also sometimes called febrile convulsions.
During most seizures the child's body becomes stiff, they lose consciousness and their arms and legs twitch. Some children may wet themselves. This is what's known as a tonic clonic seizure.
Read more about the symptoms of febrile seizures.
Frightening but harmless
Seeing a child having a seizure, particularly if they have no previous history of fits, can be frightening and distressing for the parents.
Many parents say they were convinced that their child was going to die. However, while febrile seizures may be frightening, most are harmless and do not pose a threat to a child’s health.
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. It will keep their airway open and help to prevent injury.
Stay with your child and try to make a note of how long it lasts.
If it is your child's first seizure, or it lasts longer than five minutes, take them to the nearest hospital as soon as possible or call 999 for an ambulance. While it is unlikely that there is anything seriously wrong, it is 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.
Try not to put anything, including medication, in your child’s mouth during a seizure as there is a slight chance that they might bite their tongue.
Almost all children make a complete recovery, and there is not a single reported case of a child dying as the direct result of a febrile seizure.
Read more about diagnosing febrile seizures and treating febrile seizures.
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 8 out of 10 cases. A simple febrile seizure is a fit that:
- is a tonic clonic seizure
- does not last longer than 15 minutes
- does not reoccur during the period in which your child has an illness
Complex febrile seizure
Complex febrile seizures are less common, accounting for 2 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 period in which they have an illness
- your child does not fully recover from the seizure within one hour
Why do febrile seizures happen?
The cause of febrile seizures is unknown, although it is linked to the start of a fever – a high temperature of 38ºC (100.4ºF) 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, as 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.
Who is affected?
Febrile seizures are quite common. An estimated 1 in 20 children will have at least one febrile seizure at some point. Most febrile seizures occur between the ages of six months and three years. The average age is 18 months.
Febrile seizures have been linked to an increased risk of epilepsy, as well as other problems.
Recent research has reported initial findings that 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 has not been proven and SUDC is incredibly rare, affecting only around 1 in 100,000 children (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.