A febrile seizure is a convulsion in a child caused by a spike in body temperature, often from an infection. They occur in young children with normal development without a history of neurologic symptoms. It can be frightening when your child has a febrile seizure, and the few minutes it lasts can seem like an eternity. Fortunately, they're usually harmless and typically don't indicate a serious health problem.

You can help by keeping your child safe during a febrile seizure and by offering comfort afterward. Call your doctor to have your child evaluated as soon as possible after a febrile seizure.


Usually, a child having a febrile seizure shakes all over and loses consciousness. Sometimes, the child may get very stiff or twitch in just one area of the body.

A child having a febrile seizure may:

  • Have a fever higher than 100.4 F (38.0 C)
  • Lose consciousness
  • Shake or jerk arms and legs

Febrile seizures are classified as simple or complex:

  • Simple febrile seizures. This most common type lasts from a few seconds to 15 minutes. Simple febrile seizures do not recur within a 24-hour period and are not specific to one part of the body.


When to see a doctor


  • Vomiting
  • A stiff neck
  • Breathing problems
  • Extreme sleepiness


Usually, a higher than normal body temperature causes febrile seizures. Even a low-grade fever can trigger a febrile seizure.


The fevers that trigger febrile seizures are usually caused by a viral infection, and less commonly by a bacterial infection. Influenza and the virus that causes roseola, which often are accompanied by high fevers, appear to be most frequently associated with febrile seizures.

Post-immunization seizures

The risk of febrile seizures may increase after some childhood immunizations. These include the diphtheria, tetanus and pertussis or measles-mumps-rubella vaccinations. A child can develop a low-grade fever after a vaccination. The fever, not the vaccination, causes the seizure.

Risk factors

Factors that increase the risk of having a febrile seizure include:

  • Young age. Most febrile seizures occur in children between 6 months and 5 years of age, with the greatest risk between 12 and 18 months of age.


Most febrile seizures produce no lasting effects. Simple febrile seizures don't cause brain damage, intellectual disability or learning disabilities, and they don't mean your child has a more serious underlying disorder.

Febrile seizures are provoked seizures and don't indicate epilepsy. Epilepsy is a condition characterized by recurrent unprovoked seizures caused by abnormal electrical signals in the brain.

Recurrent febrile seizures


  • Your child's first seizure resulted from a low fever.
  • An immediate family member has a history of febrile seizures.
  • Your child was younger than 18 months at the time of the first febrile seizure.



Giving your child medications

Giving your child infants' or children's acetaminophen (Children's Non-Aspirin Tylenol, others) or ibuprofen (Infants' Motrin, Children's Motrin, others) at the beginning of a fever may make your child more comfortable, but it won't prevent a seizure.


Prescription prevention medications


Rectal diazepam (Diastat) or nasal midazolam might be prescribed to be used as needed for children who are prone to long febrile seizures. These medications are typically used to treat seizures that last longer than five minutes or if the child has more than one seizure within 24 hours. They are not typically used to prevent febrile seizures.

June 18, 2019
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