Cause and Risk Factors for Febrile Seizures

Febrile seizures are caused by fever, usually higher than 102°F (38.8°C). There are several risk factors for febrile seizures. When more than one risk factor is present, the risk is even higher.

Risk factors for febrile seizures include the following:

  • Age (occurs between the ages of 3 months and 5 years)
  • Developmental delays (e.g., cerebral palsy, mental retardation)
  • Family history of seizure disorders
  • Frequent fevers (e.g., caused by viral or bacterial infection)
  • High fever (above 102°F)
  • Maternal smoking and alcohol use during pregnancy (further research is needed to confirm this link)
  • Meningitis (inflammation of the membranes that surround the brain and spinal cord)
  • Personal history (i.e., previous febrile seizure)

Certain pathogens (disease-causing organisms; e.g., viruses, bacteria) are associated with an increased risk for febrile seizures. These pathogens include influenza A virus, which causes the flu, human herpesvirus 6 (HHV-6), which causes roseola, and Shigella and Campylobacter bacteria, which cause gastroenteritis (e.g., diarrhea, nausea, vomiting, fever).

Children who were hospitalized as newborns and children who are in day care are at increased risk for fevers and febrile seizures. Childhood immunizations and urinary tract infections (UTIs) also may increase the risk.

Children who have a febrile seizure before the age of 1 year, children who have a seizure associated with a relatively mild fever (below 102°F), and children who experience a seizure quickly after developing a fever are at increased risk for additional febrile seizures.

Publication Review By: Stanley J. Swierzewski, III, M.D.

Published: 27 Aug 2008

Last Modified: 15 Sep 2015