Fever Seizures

Topic Overview

Fever seizures (sometimes called fever convulsions) are uncontrolled muscle spasms that can occur in children who have a rapid increase in body temperature. You may not even know your child has a fever. The rapid increase in body temperature in a short period of time may cause the fever seizure. Once a fever has reached a high temperature, the risk of a seizure is probably over. Most children who have a fever seizure have temperatures above 102°F (39°C).

Fever seizures can be frightening but they are not usually harmful to the child and do not cause long-term problems, such as brain damage, intellectual disabilities, or learning problems.

Fever seizures affect 2% to 5% of children. Children can have another seizure. The chance of another fever seizure varies with age, but between 30% and 50% will have another within a year of the first one. These seizures are not a form of epilepsy.

A child who is having a seizure often loses consciousness and shakes, moving his or her arms and legs on both sides of the body. The child's eyes may roll back. The child may stop breathing for a few seconds and might also vomit, urinate, or pass stools. It is important to protect the child from injury during a seizure.

Fever seizures usually last 1 to 3 minutes. After the seizure, the child may be sleepy. You can let the child sleep, but check the child frequently for changes in color or breathing, or twitching arms or legs. The child also may seem confused after the seizure, but normal behavior and activity level should return within 60 minutes of the seizure.

A seizure is more likely to have been caused by a fever if the seizure occurred within 24 hours of the start of a fever. Fever seizures usually affect the whole body, not just one side. Most children have never had a fever seizure before and they also do not have other nervous system (neurologic) problems.

Use the Check Your Symptoms section to decide if and when your child should see a doctor.

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Author:	Jan Nissl, RN, BS	Last Updated: April 21, 2009
Medical Review:	Michael J. Sexton, MD - Pediatrics Kathleen Romito, MD - Family Medicine Thomas Emmett Francoeur, MDCM, CSPQ, FRCPC - Pediatrics H. Michael O'Connor, MD - Emergency Medicine
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