A febrile seizure is a convulsion (shaking, twitching, muscle tightness) or fainting associated with a fever. A febrile seizure occurs in infants or small children. This seizure is not associated with any other illness or medical condition except the fever.

There are 2 types of febrile seizures:

  • Simple febrile seizures:
    • Convulsions last between a few seconds to 15 minutes with recovery taking about an hour
    • Seizures are followed by a period of confusion and sleepiness which slowly goes away
  • Complex febrile seizures:
    • Last longer than 15 minutes
    • Occur more than once within 24 hours
    • Convulsions which affect only part of the body

Febrile seizures can be alarming. Fortunately, children tend to outgrow these seizures. There is also a low risk for long-term physical or mental disorders.


High body temperature due to a fever is believed to trigger the seizure. The fever is most often caused by common viral infections. Some febrile seizures may be caused by fever after routine immunizations.

Risk Factors

Age is the greatest risk factor. Febrile seizures occur between ages 3 months and 5 years. Most febrile seizures occur in children between ages 6 months and 3 years. In general, the younger the age that the first febrile seizure occurs, the more likely it is that a child will have another seizure.

There is some evidence that febrile seizures may run in families.


A seizure typically lasts a few seconds to a few minutes. Signs of a febrile seizure include:

  • A fever, usually above 102°F (38.9°C)
  • Convulsion—jerking or stiffening muscles
  • Abnormal eye movements
  • Coarse breathing sounds during the convulsion
  • Loss of consciousness
  • Loss of bladder or bowel control
  • Vomiting
  • Brief period of drowsiness or confusion following a seizure

If you suspect your child is having a febrile seizure, stay calm and follow these steps:

  • Unless the doctor has told you otherwise, call for emergency medical services.
  • Protect your child from physical injury. Place your child on the floor or bed away from any hard or sharp objects.
  • Protect your child's airway. Do not place anything in the mouth during the convulsion. Turn the child’s head or body to the side. This will allow saliva or vomit to drain from the mouth.
  • Watch the time. The length of the convulsions should be less than 5 minutes.


Febrile seizure is diagnosed based on information about the seizure and your child's health.

Your child's bodily fluids may be tested. This can be done with:

Images may be taken of your child's head. This can be done with:

Your child's brain function may be tested. This can be done with an electroencephalogram (EEG).

MRI Scan

MRI of the Brain
Copyright © Nucleus Medical Media, Inc.


Children will eventually outgrow febrile seizures. The treatment goal is to manage fevers that may cause seizures. This may be done by treating the underlying infection. The treatments may include medication.

To address the underlying cause of fever, the child's doctor may advise:

  • Antibiotics
  • Antiviral medications
  • Acetaminophen or ibuprofen to lower the fever

A rectal valium gel may be advised. This gel can interrupt seizures. It may be recommended if the child has frequent seizures and the seizure lasts more than 4-5 minutes.


Fevers can happen suddenly. A seizure can be the first sign. As a result, there is no known way to prevent a febrile seizure.