A febrile seizure is a convulsion in a child that’s caused by a fever. The fever is often from an infection. Febrile seizures occur in young, healthy children who have normal development and haven’t had any neurological symptoms before.

It can be frightening when your child has a febrile seizure. Fortunately, febrile seizures are usually harmless, only last a few minutes, 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 the 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.
• Complex febrile seizures. This type lasts longer than 15 minutes, occurs more than once within 24 hours or is confined to one side of your child’s body.

Febrile seizures most often occur within 24 hours of the onset of a fever and can be the first sign that a child is ill.

See your child’s doctor as soon as possible after your child’s first febrile seizure, even if it lasts only a few seconds. Call an ambulance to take your child to the emergency room if the seizure lasts longer than five minutes or is accompanied by:

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