Febrile Seizures: What You Need to Know

What Are Seizures?

Seizures are caused by abnormal (not normal) electrical activity in the brain. Seizures usually last from seconds to minutes. The most common type of seizure is a generalized tonic-clonic seizure, sometimes called a convulsion. This is when a person loses consciousness (passes out). Their arms and legs may become stiff and shake.

What Are Febrile Seizures?

A febrile seizure is a type of seizure that is caused by a fever of over 100.4°F (38°C) in a child under age 6. Febrile seizures are common. They tend to happen most often between 12 to 18 months of age. Febrile seizures can be frightening, but they are not usually dangerous and do not cause brain damage.

Does My Child Need Testing If They Have a Febrile Seizure?

Most children who have febrile seizures do not need lab tests or imaging.

Your child may need more testing if the febrile seizure:

• Lasts longer than 5 minutes
• Happens more than once in 24 hours
• Affects only one side of the body

Additional testing may include lab tests, imaging (like MRI scans) or EEG (electroencephalogram, where wires are placed on the scalp to measure brain activity).

If My Child Had a Febrile Seizure in the Past, Does That Mean There is a Higher Chance of Having Another Febrile Seizure?

Children who have had a febrile seizure are more likely to have another one. About 3 out of 10 children who have one febrile seizure will have a second febrile seizure before they turn 6 years old.

If My Child Had a Febrile Seizure, Does That Mean They Will Develop Epilepsy?

Epilepsy is when a person has 2 or more seizures without cause. Since febrile seizures are caused by a fever, this does not mean that your child has epilepsy. The chance of developing epilepsy is slightly higher than that of children who do not have febrile seizures.

How Is It Treated and What Should I Do For My Child After a Febrile Seizure?

• If your child has a fever, acetaminophen (Tylenol®) and/or ibuprofen (Advil® or Motrin®) can help bring down the fever. While this may not prevent future febrile seizures, it can help your child stay more comfortable.
• If your child has another febrile seizure, contact your child’s pediatrician right away for next steps.
• If your child has a seizure lasting 5 minutes or longer, or if they turn blue or have trouble breathing during the seizure, call 911 for an ambulance and go to the nearest emergency room.
• Contact the doctor if you notice any new abnormal movements, staring spells, or loss of consciousness. Your child’s doctor can help decide if your child is having seizures or another medical concern.

Rev. 9/2020. Mass General for Children and Massachusetts General Hospital do not endorse any of the brands listed on this handout. This handout is intended to provide health information so that you can be better informed. It is not a substitute for medical advice and should not be used to treatment of any medical conditions.