Health Encyclopedia

 

 

Fever Seizures

Topic Overview

Fever seizures (sometimes called fever convulsions or febrile seizures) can occur in children who have a rapid increase in body temperature. You may not even know that your child has a fever. The rapid increase in body temperature in a short period of time may happen at the same time as the fever seizure. After 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).

A seizure is likely to be fever-related if:

  • There is one seizure in a 24-hour period.
  • The seizure lasted less than 15 minutes.
  • The seizure affected the entire body, not just one side of the body.
  • The child is between 6 months and 5 years old.
  • The child does not have nervous system (neurological) problems.
  • The child has had fever seizures before.

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 about 30% to 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 him or her frequently for changes in color or breathing, or for 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.

Check your child's symptoms to decide if and when your child should see a doctor.

Check Your Symptoms

Has your child had a fever seizure?
Fever seizures are uncontrolled muscle spasms that can happen when a child's body temperature goes up quickly.
Yes
Fever seizure
No
Fever seizure
How old are you?
Less than 6 months
Less than 6 months
6 months to 2 years
6 months to 2 years
3 to 6 years
3 to 6 years
7 years or older
7 years or older
Are you male or female?
Male
Male
Female
Female
Is this your child's first seizure?
Yes
First seizure
No
First seizure
Have the child's other seizures occurred during the same illness (within the past day or so)?
Yes
Seizures occurred during same illness
No
Seizures occurred during same illness
Has the seizure lasted more than 3 minutes?
Yes
Seizure lasting more than 3 minutes
No
Seizure lasting more than 3 minutes
Does your child have symptoms of shock?
Yes
Signs of shock
No
Signs of shock
Does your child have symptoms of heatstroke?
Yes
Heatstroke symptoms
No
Heatstroke symptoms
Do you think your child may be dehydrated?
It can be harder to tell in a baby or young child than it is in an older child.
Yes
May be dehydrated
No
May be dehydrated
Are the symptoms severe, moderate, or mild?
Severe
Severe dehydration
Moderate
Moderate dehydration
Mild
Mild dehydration
Is your child having trouble drinking enough to replace the fluids he or she has lost?
Little sips of fluid usually are not enough. The child needs to be able to take in and keep down plenty of fluids.
Yes
Unable to drink enough fluids
No
Able to drink enough fluids
Is your child having trouble breathing (more than a stuffy nose)?
Yes
Difficulty breathing more than stuffy nose
No
Difficulty breathing more than stuffy nose
Would you describe the breathing problem as severe, moderate, or mild?
Severe
Severe difficulty breathing
Moderate
Moderate difficulty breathing
Mild
Mild difficulty breathing
Does your child have symptoms of a serious illness?
Yes
Symptoms of serious illness
No
Symptoms of serious illness
Does your child have symptoms of a joint infection?
Yes
Symptoms of a joint infection
No
Symptoms of a joint infection
Have tiny red or purple spots or bruises appeared suddenly?
Yes
Sudden appearance of red or purple spots or bruising
No
Sudden appearance of red or purple spots or bruising
Does your child have pain?
Yes
Pain
No
Pain
How bad is the pain on a scale of 0 to 10, if 0 is no pain and 10 is the worst pain you can imagine?
8 to 10: Severe pain
Severe pain
5 to 7: Moderate pain
Moderate pain
1 to 4: Mild pain
Mild pain
Do you think your child has a fever?
Yes
Fever
No
Fever
Did you take your child's temperature?
Yes
Temperature taken
No
Temperature taken
How high is the fever? The answer may depend on how you took the temperature.
High: 104°F (40°C) or higher, oral
High fever: 104°F (40°C) or higher, oral
Moderate: 100.4°F (38°C) to 103.9°F (39.9°C), oral
Moderate fever: 100.4°F (38°C) to 103.9°F (39.9°C), oral
Mild: 100.3°F (37.9°C) or lower, oral
Mild fever: 100.3°F (37.9°C) or lower, oral
How high do you think the fever is?
High
Feels fever is high
Moderate
Feels fever is moderate
Mild or low
Feels fever is mild
Does your child have a health problem or take medicine that weakens his or her immune system?
Yes
Disease or medicine that causes immune system problems
No
Disease or medicine that causes immune system problems

If you're not sure if a child's fever is high, moderate, or mild, think about these issues:

With a high fever:

  • The child feels very hot.
  • It is likely one of the highest fevers the child has ever had.

With a moderate fever:

  • The child feels warm or hot.
  • You are sure the child has a fever.

With a mild fever:

  • The child may feel a little warm.
  • You think the child might have a fever, but you're not sure.

Severe dehydration means:

  • The child's mouth and eyes may be extremely dry.
  • The child may pass little or no urine for 12 or more hours.
  • The child may not seem alert or able to think clearly.
  • The child may be too weak or dizzy to stand.
  • The child may pass out.

Moderate dehydration means:

  • The child may be a lot more thirsty than usual.
  • The child's mouth and eyes may be drier than usual.
  • The child may pass little or no urine for 8 or more hours.
  • The child may feel dizzy when he or she stands or sits up.

Mild dehydration means:

  • The child may be more thirsty than usual.
  • The child may pass less urine than usual.

Symptoms of serious illness in a baby may include the following:

  • The baby is limp and floppy like a rag doll.
  • The baby doesn't respond at all to being held, touched, or talked to.
  • The baby is hard to wake up.

Severe dehydration means:

  • The baby may be very sleepy and hard to wake up.
  • The baby may have a very dry mouth and very dry eyes (no tears).
  • The baby may have no wet diapers in 12 or more hours.

Moderate dehydration means:

  • The baby may have no wet diapers in 6 hours.
  • The baby may have a dry mouth and dry eyes (fewer tears than usual).

Mild dehydration means:

  • The baby may pass a little less urine than usual.

Severe trouble breathing means:

  • The child cannot eat or talk because he or she is breathing so hard.
  • The child's nostrils are flaring and the belly is moving in and out with every breath.
  • The child seems to be tiring out.
  • The child seems very sleepy or confused.

Moderate trouble breathing means:

  • The child is breathing a lot faster than usual.
  • The child has to take breaks from eating or talking to breathe.
  • The nostrils flare or the belly moves in and out at times when the child breathes.

Mild trouble breathing means:

  • The child is breathing a little faster than usual.
  • The child seems a little out of breath but can still eat or talk.

Babies can quickly get dehydrated when they lose fluids because of problems like vomiting or fever.

Symptoms of dehydration can range from mild to severe. For example:

  • The baby may be fussy or cranky (mild dehydration), or the baby may be very sleepy and hard to wake up (severe dehydration).
  • The baby may have a little less urine than usual (mild dehydration), or the baby may not be urinating at all (severe dehydration).

Symptoms of difficulty breathing in a baby or young child can range from mild to severe. For example:

  • The child may be breathing a little faster than usual (mild difficulty breathing), or the child may be having so much trouble that the nostrils are flaring and the belly is moving in and out with every breath (severe difficulty breathing).
  • The child may seem a little out of breath but is still able to eat or talk (mild difficulty breathing), or the child may be breathing so hard that he or she cannot eat or talk (severe difficulty breathing).

Sudden tiny red or purple spots or sudden bruising may be early symptoms of a serious illness or bleeding problem. There are two types.

Petechiae (say "puh-TEE-kee-eye"):

  • Are tiny, flat red or purple spots in the skin or the lining of the mouth.
  • Do not turn white when you press on them.
  • Range from the size of a pinpoint to the size of a small pea and do not itch or cause pain.
  • May spread over a large area of the body within a few hours.
  • Are different than tiny, flat red spots or birthmarks that are present all the time.

Purpura (say "PURR-pyuh-ruh" or “PURR-puh-ruh”):

  • Is sudden, severe bruising that occurs for no clear reason.
  • May be in one area or all over.
  • Is different than the bruising that happens after you bump into something.

Try Home Treatment

You have answered all the questions. Based on your answers, you may be able to take care of this problem at home.

  • Try home treatment to relieve the symptoms.
  • Call your doctor if symptoms get worse or you have any concerns (for example, if symptoms are not getting better as you would expect). You may need care sooner.

Many things can affect how your body responds to a symptom and what kind of care you may need. These include:

  • Your age. Babies and older adults tend to get sicker quicker.
  • Your overall health. If you have a condition such as diabetes, HIV, cancer, or heart disease, you may need to pay closer attention to certain symptoms and seek care sooner.
  • Medicines you take. Certain medicines, herbal remedies, and supplements can cause symptoms or make them worse.
  • Recent health events, such as surgery or injury. These kinds of events can cause symptoms afterwards or make them more serious.
  • Your health habits and lifestyle, such as eating and exercise habits, smoking, alcohol or drug use, sexual history, and travel.

Symptoms of heatstroke may include:

  • Feeling or acting very confused, restless, or anxious.
  • Trouble breathing.
  • Sweating heavily, or not sweating at all (sweating may have stopped).
  • Skin that is red, hot, and dry, even in the armpits.
  • Passing out.
  • Seizure.

Heatstroke occurs when the body can't control its own temperature and body temperature continues to rise.

Seizures

Call 911 Now

Based on your answers, you need emergency care.

Call 911 or other emergency services now.

Seek Care Today

Based on your answers, you may need care soon. The problem probably will not get better without medical care.

  • Call your doctor today to discuss the symptoms and arrange for care.
  • If you cannot reach your doctor or you don't have one, seek care today.
  • If it is evening, watch the symptoms and seek care in the morning.
  • If the symptoms get worse, seek care sooner.

Symptoms of difficulty breathing can range from mild to severe. For example:

  • You may feel a little out of breath but still be able to talk (mild difficulty breathing), or you may be so out of breath that you cannot talk at all (severe difficulty breathing).
  • It may be getting hard to breathe with activity (mild difficulty breathing), or you may have to work very hard to breathe even when you’re at rest (severe difficulty breathing).

Seek Care Now

Based on your answers, you may need care right away. The problem is likely to get worse without medical care.

  • Call your doctor now to discuss the symptoms and arrange for care.
  • If you cannot reach your doctor or you don't have one, seek care in the next hour.
  • You do not need to call an ambulance unless:
    • You cannot travel safely either by driving yourself or by having someone else drive you.
    • You are in an area where heavy traffic or other problems may slow you down.

Shock is a life-threatening condition that may occur quickly after a sudden illness or injury.

Symptoms of shock in a child may include:

  • Passing out.
  • Being very sleepy or hard to wake up.
  • Not responding when being touched or talked to.
  • Breathing much faster than usual.
  • Acting confused. The child may not know where he or she is.

Temperature varies a little depending on how you measure it. For children up to 11 years old, here are the ranges for high, moderate, and mild according to how you took the temperature.

Oral (by mouth), ear, or rectal temperature

  • High: 104 F (40 C) and higher
  • Moderate: 100.4 F (38 C) to 103.9 F (39.9 C)
  • Mild: 100.3 F (37.9 C) and lower

Armpit (axillary) temperature

  • High: 103°F (39.5°C) and higher
  • Moderate: 99.4 F (37.4 C) to 102.9 F (39.4 C)
  • Mild: 99.3°F (37.3°C) and lower

Note: For children under 5 years old, rectal temperatures are the most accurate.

You can get dehydrated when you lose a lot of fluids because of problems like vomiting or fever.

Symptoms of dehydration can range from mild to severe. For example:

  • You may feel tired and edgy (mild dehydration), or you may feel weak, not alert, and not able to think clearly (severe dehydration).
  • You may pass less urine than usual (mild dehydration), or you may not be passing urine at all (severe dehydration).

Pain in children 3 years and older

  • Severe pain (8 to 10): The pain is so bad that the child can't stand it for more than a few hours, can't sleep, and can't do anything else except focus on the pain. No one can tolerate severe pain for more than a few hours.
  • Moderate pain (5 to 7): The pain is bad enough to disrupt the child's normal activities and sleep, but the child can tolerate it for hours or days.
  • Mild pain (1 to 4): The child notices and may complain of the pain, but it is not bad enough to disrupt his or her sleep or activities.

Symptoms of a joint infection may include:

  • Severe pain.
  • Swelling.
  • Sudden redness over or around the joint.
  • Warmth in or around a joint.
  • Not being able to move the joint because of pain or swelling.
  • Pus draining from the area.

Certain health conditions and medicines weaken the immune system's ability to fight off infection and illness. Some examples in children are:

  • Diseases such as diabetes, cystic fibrosis, sickle cell disease, and congenital heart disease.
  • Steroid medicines, which are used to treat a variety of conditions.
  • Medicines taken after organ transplant.
  • Chemotherapy and radiation therapy for cancer.
  • Not having a spleen.

Symptoms of serious illness may include:

  • A severe headache.
  • A stiff neck.
  • Mental changes, such as feeling confused or much less alert.
  • Extreme fatigue (to the point where it's hard for you to function).
  • Shaking chills.

Home Treatment

Protect your child from injury during a seizure:

  • Ease the child to the floor, or lay a very small child facedown on your lap. Do not restrain the child.
  • Turn the child onto his or her side, which will help clear the mouth of any vomit or saliva. This will help keep the tongue from blocking the air passage so the child can breathe. Keeping the head and chin forward (in the same position as when you sniff a flower) also will help keep the air passage open.
  • Loosen clothing.
  • Do not put anything in the child's mouth to prevent tongue-biting. This could cause injury.
  • Try to stay calm, which will help calm the child. Comfort the child with quiet, soothing talk.
  • Time the length of the seizure and pay close attention to the child's behavior during the seizure so you can describe it to your child's doctor.

Check your child for injuries after the seizure:

  • If the child is having trouble breathing, turn his or her head to the side and, using your finger, gently clear the mouth of any vomit or saliva to aid breathing.
  • If the child does not need to see a doctor right away, put him or her in a cool room to sleep. Sleepiness is common following a seizure. Check on the child often. Normal behavior and activity level should return within 60 minutes of the seizure.

If your child has had a fever seizure in the past and you have talked with your child's doctor about how to care for your child after a seizure, be sure to follow the doctor's instructions.

For home treatment of a fever, see the topic Fever or Chills, Age 11 and Younger.

Symptoms to watch for during home treatment

Call your doctor if any of the following occur during home treatment:

  • Another seizure occurs with the same fever illness.
  • Other symptoms of illness develop, such as an infection.
  • Symptoms become more severe or frequent.

Prevention

The best way to prevent fevers is to reduce your child's exposure to infectious diseases. Hand-washing is the single most important prevention measure for people of all ages.

Preparing For Your Appointment

To prepare for your appointment, see the topic Making the Most of Your Appointment.

You may feel upset after seeing a fever seizure. Stay calm. You can help your child's doctor diagnose and treat your child's condition by being prepared to answer the following questions:

  • What is the history of the fever?
    • When did the fever start?
    • Did it come on suddenly or increase over several hours?
    • How high is the fever?
    • Does the child have any other symptoms?
  • Does your child have frequent fevers? How long do they usually last?
  • How was the child's health and behavior before the seizure?
  • Had the child had an accident or an injury before the seizure?
  • What happened during the seizure?
  • What kind of body movements were there?
  • How long did the seizure last?
  • How did the child act immediately after the seizure?
  • Have you noted any injuries from the seizure?
  • Has the child ever had a seizure before?
  • What other health problems, if any, has the child had over the past 3 months?
  • Has your child been eating, drinking, and playing normally?
  • What home treatment measures, including nonprescription medicines, have you used? Did they help?
  • Does your child have any health risks?

Ask your child's doctor what you can do to prevent another seizure and what to do if another seizure occurs.

Related Information

References

Other Works Consulted

  • American Academy of Pediatrics (2008). Clinical Practice Guideline for the Long-term Management of the Child With Simple Febrile Seizures. Elk Grove Village, IL: American Academy of Pediatrics.

Credits

By Healthwise Staff
Primary Medical Reviewer William H. Blahd, Jr., MD, FACEP - Emergency Medicine
Specialist Medical Reviewer H. Michael O'Connor, MD - Emergency Medicine
Last Revised September 13, 2012

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

© 1995-2013 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.