Febrile Seizures


What Is It?

The brain’s nerve cells (neurons) communicate with each other by giving off tiny electric signals. When someone has a seizure (convulsion), the way the brain’s nerve cells give off signals suddenly changes, causing different muscles in the body to twitch or jerk uncontrollably. A seizure may affect only a small area of the brain and body (focal seizure), or it may involve the whole brain and body (generalized seizure).

Febrile seizures occur in children, and are caused by fever of at least 102 degrees Fahrenheit or by a sudden rise in body temperature. These febrile seizures usually happen at the beginning of an illness, soon after the fever appears. They affect about 3 percent of children and are most common between the ages of 6 months and 5 years.

Children are more likely to have a febrile seizure if:

  • They have had febrile seizures before
  • Other family members (brothers, sisters, parents) have had febrile seizures
  • They have delays in normal development

About one in three children who have had a febrile seizure will have another one within one year, but most children eventually grow out of this condition. The risk of having another seizure is greater in children with a family history of febrile seizures and in children who had their first seizure when they were younger than 12 months old.


Signs of a febrile seizure may include:

  • Jerky, twitching movements of the arms and legs
  • Stiffness
  • Rolling eyes
  • Loss of consciousness (passing out)
  • Not responding to voices or touch


In most cases, a doctor can diagnose febrile seizures based on a description of the episode. However, the doctor may want to see your child to look for the cause of the fever. In particular, the doctor will want to make sure your child does not have any signs of a serious infection of the brain (encephalitis) or of the membranes that cover the brain and spinal cord (meningitis).

Expected Duration

Febrile seizures usually last only a few minutes. If they last longer than this, call your doctor right away.


There is nothing that can be done to prevent first-time febrile seizures. In children who already have had one febrile seizure, some medications may help to prevent more seizures. However, the potential side effects of these drugs for your child may be worse than the benefits. The American Academy of Pediatrics does not recommend the use of these medications except in special circumstances. Instead, it recommends that parents of children at risk of febrile seizures be taught how best to manage a fever and what to do if a child has a seizure.


You cannot stop a seizure once it has started, but you can do the following to protect your child:

  • Try to stay calm.
  • Place the child on his or her side or stomach on a safe, flat surface, such as the floor, away from furniture or things that may cause injury.
  • Tilt your child’s head to the side to prevent choking.
  • Do not restrain your child or put anything between his or her teeth.
  • Observe your child carefully so you can describe the events to your doctor.
  • Keep track of the time. If the seizure lasts longer than about five minutes, call your doctor.

After a seizure, call your doctor to arrange an appointment so your child can be examined.

Treatment involves reducing the fever and treating whatever is causing the fever. Hospitalization usually is not necessary, unless the condition causing the fever requires it.


The prognosis is excellent, as febrile seizures generally are not harmful and do not cause long-term problems. Children with cerebral palsy, developmental delays or certain neurological problems are slightly more likely than other children to develop epilepsy (repeated seizures that are not fever-related) after febrile seizures. Children who have repeated febrile seizures and who have their first seizure when they are younger than 12 months old are also at an increased risk of developing epilepsy. However, the risk is still very low.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.