Febrile Seizures

Febrile seizures are seizures that happen in children because of a fever. These seizures are usually short-lived and harmless. The overwhelming majority of children who have them will recover quickly and won’t experience any long-term effects or complications. But between 2.5% and 5% of children who have complex febrile seizures will develop epilepsy.

Overview

What are febrile seizures?

A fever causes a febrile seizure in your child. These types of seizures are age-specific, happening in infants as young as 6 months and children up to 5 years old. Febrile seizures most commonly occur between 12 and 18 months of age. They’re usually harmless, and most don’t have a lasting effect.

Complex vs. simple febrile seizures

Simple febrile seizures are those that have all three of the following:

  • They affect both sides of your child’s body. A seizure that affects both sides of your child’s body is “generalized” (as opposed to focal seizures, which only affect one side of their body).
  • They’re short-lived. Simple febrile seizures last fewer than 15 minutes.
  • They’re isolated events. Simple febrile seizures don’t happen more than once within 24 hours.

If any of the three above criteria aren’t true, it’s a complex febrile seizure. Complex febrile seizures are more likely to require treatment and may suggest an increased risk of seizure disorders later in life.

What are the three main signs and symptoms of febrile seizures?

Hallmark symptoms of a febrile seizure include:

  • Shaking all over. A child who’s having a febrile seizure loses control of muscle movements on one or both sides of their body. This usually involves shaking, stiffening or tensing up.
  • Loss of consciousness. Your child may pass out, or their eyes might roll back. Loss of consciousness can happen with or without shaking.
  • Loss of control. Your child may vomit, drool, urinate (pee) or defecate (poop).
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Possible Causes

What causes febrile seizures?

Fever causes febrile seizures. Febrile seizures are most common during the first day of an illness as a child's temperature rises. They're most likely with a fever of at least 100.4 degrees Fahrenheit (38 degrees Celsius). In some cases, children will sometimes have a seizure before developing a fever.

Fevers from viral infections usually trigger febrile seizures. But the fevers may be due to any type of infection, including:

(Note: Some childhood vaccinations may cause fever, and if a child has a febrile seizure after vaccination, it is the fever, not the vaccine itself, that causes the seizure.)

Febrile seizure risk goes up after having one

Children who have one febrile seizure have a higher chance of having another later on. The risk of a child having a second febrile seizure is about 1 in 3. About 10% of children who have one febrile seizure will have three or more throughout their entire childhood. The risk is highest in children who have a febrile seizure before turning 1 year old.

Care and Treatment

How are febrile seizures treated?

Simple febrile seizures usually don’t need treatment. They rarely last more than a few minutes, and children recover quickly from them. Parents can give fever-reducing medications during febrile illnesses, such as acetaminophen (Tylenol) or ibuprofen (Motrin), but these may not prevent febrile seizures from happening.

Complex febrile seizures are more likely to need treatment. For children who tend to have prolonged febrile seizures, rectal diazepam (Diastat) may be prescribed for home use. This is typically used in case of a seizure that last longer than five minutes or if the child has more than one seizure in 24 hours.

Rarely, daily prescription antiseizure medications are used to prevent febrile seizures. In most cases, this is not necessary.

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What can I do at home to treat this symptom?

You shouldn’t try to treat a first-time febrile seizure at home. A first-time febrile seizure needs immediate medical care to make sure that it isn’t another kind of seizure or that it isn’t happening because of a severe infection like meningitis or encephalitis (both of which can be life-threatening).

If your child has a history of febrile seizures, your healthcare provider can guide you on what to do to treat these at home. In general, you should do the following:

  • Stay calm. Seeing your child having a seizure can be very frightening, but it’s important for you to keep as calm as possible.
  • Track the time. Note how long your child’s seizure lasts. If the seizure lasts five minutes or more and isn’t slowing down or stopping, you should immediately call 911 (or your local emergency services number).
  • Slowly and gently set your child down on the floor. Don’t set a child on a table or bed (they could fall), and don't try to hold them in your arms or hold them down (that increases the risk of an injury).
  • Place them in the rescue position. Lay your child on their left side with their lower arm stretched straight out, so it's like a cushion for their head. This helps prevent choking from fluid (saliva or vomit) going into their lungs.
  • Don’t put anything in their mouth. That could result in an injury for your child or you.

How can this symptom be prevented?

Febrile seizures happen unpredictably and are usually not preventable.

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When to Call the Doctor

When should this symptom be treated by a doctor or healthcare provider?

All first-time febrile seizures need emergency medical care in a hospital emergency room or another kind of emergency setting.

If your child has a history of febrile seizures, your child’s pediatrician can offer the best guidance on what you can and should do to treat these seizures. They can also tell you any signs that your child needs medical care.

In general, you should call your child’s pediatrician in the following cases:

  • If your child has a febrile seizure and they’ve had them before.
  • If your child is slow to recover from a febrile seizure (if they take an hour or more to return to normal).

When to get emergency medical care

You should get emergency medical care for febrile seizures in any of the following situations:

  • If this is the first febrile seizure your child has experienced.
  • If a febrile seizure lasts at least five minutes and isn’t stopping or slowing down.
  • If your child has trouble breathing.
  • If your child also has symptoms of a brain or spinal cord infection. These symptoms include neck stiffness or pain, lethargy (if your child is not very active and has little or no reaction to what's happening around them) or frequent vomiting.

Additional Common Questions

Do febrile seizures cause permanent effects?

Simple febrile seizures are typically harmless. Researchers have found no evidence of long-term harm from simple febrile seizures. There’s also little to no evidence that simple febrile seizures increase the risk of developing epilepsy.

Complex febrile seizures are associated with a slightly increased chance of future seizure disorders. According to the available research, between 2.5% and 5% of children with complex febrile seizures will develop epilepsy. However, most children who have complex febrile seizures don’t have any long-term effects.

A note from Cleveland Clinic

Febrile seizures can be frightening, especially if your child has never had one before. However, most febrile seizures are short-lived, and children quickly recover from them without any long-term effects. If you have questions or concerns, you should talk to your child’s pediatrician. They can offer guidance and information that can help you understand the risks. They can also help set your mind at ease and show you how to do seizure first aid, so you can feel prepared if your child has a febrile seizure in the future.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 04/23/2022.

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