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Excessive Daytime Sleepiness, Hypersomnia, and Narcolepsy

What is excessive daytime sleepiness?

Excessive daytime sleepiness means your child feels extremely sleepy during the day. They may sleep longer at night, take naps during the day, or fall asleep at times you would not expect, such as at school or during play.    

Excessive daytime sleepiness can have many causes. These include:  

  • Not getting enough sleep 
  • Medicine side effects 
  • Sleep apnea 
  • Depression 
  • Brain injury 
  • Hormone problems 
  • Certain sleep disorders 

Hypersomnia and narcolepsy are 2 sleep disorders that cause excessive daytime sleepiness.  

  • Hypersomnia causes your child to get very sleepy during the day, even after getting enough sleep.  
  • Narcolepsy is a disorder in which your child’s sleep-wake cycles are disrupted. They may have trouble staying awake during the day or may fall asleep at unexpected times.   

Children and teens with certain types of brain tumors and certain other serious illnesses may be more likely to have hypersomnia or narcolepsy than other children.  

Some children may briefly fall asleep, sometimes without knowing it. This is called a microsleep. After a microsleep, your child may feel like they zoned out or stopped paying attention for a short time. 

Excessive daytime sleepiness may not go away with extra sleep, especially if it is caused by a sleep disorder. But getting enough sleep and healthy sleep habits can improve alertness and daily function. 

Care providers may use sleep tests in a sleep lab to help understand why your child is very sleepy during the day and whether they have hypersomnia or narcolepsy. 

Treatment may include medicine to help your child stay alert during the day or to sleep better at night. Your care team may help your child practice healthy sleep habits to help them have more energy during the day. 

  1. What is hypersomnia?

    Hypersomnia means that a person feels very sleepy or drowsy, no matter how much sleep or rest they get. Hypersomnia can be related to a medical condition or other sleep disorder. Sometimes it happens without a known cause, a condition called idiopathic hypersomnia.   

    Symptoms of hypersomnia 

    Symptoms of hypersomnia include: 

    • Being extremely sleepy or drowsy during the day (somnolence) 
    • Having trouble waking up or staying awake 
    • Feeling groggy or confused after waking up 
    • Sleeping longer at night or napping more during the day 
    • Feeling unrested after sleep 
    • Having trouble thinking or concentrating (brain fog) 
    • Feeling low in energy  
    • Having problems keeping up at school or doing daily tasks 

    Causes of hypersomnia 

    Many factors can lead to hypersomnia. These include: 

    Children with a type of brain tumor called craniopharyngioma are at risk for hypersomnia. These tumors develop near the hypothalamus, a brain structure that controls sleep and wake. Hypersomnia may develop because of the tumor itself or after treatment, such as surgery. 

    Diagnosis of hypersomnia 

    The care team will do a patient and family interview or questionnaire, a health history, and a physical exam. They will review your child’s medicines to find out if any of them may cause your child’s sleepiness. They may ask your child to keep a sleep diary to track daytime and nighttime sleep. 

    Tests may include: 

    • Blood tests to look for changes in blood counts, hormones, and organ function  
    • Sleep study (polysomnography) to measure brain, muscle, heart rate, and breathing activity during overnight sleep  
    • Multiple sleep latency test (MSLT) to measure sleep patterns during the day 
    • Activity monitor (actigraphy) to track sleep-wake patterns over several days 

  2. What is narcolepsy?

    Narcolepsy is a sleep disorder that affects how the brain controls sleep and wake patterns. A person with narcolepsy has trouble staying awake during the day and may fall asleep quickly or at unexpected times, such as at school.   

    Symptoms of narcolepsy

    Symptoms of narcolepsy include:

    • Feeling extremely sleepy or drowsy during the day (somnolence)
    • Falling asleep suddenly or at unexpected times or places (sleep attacks)
    • Having sudden muscle weakness or trouble moving, often triggered by emotions (cataplexy)
    • Waking up often during the night 
    • Having brief times when your child cannot move or speak while falling asleep or waking up (sleep paralysis)
    • Having vivid dream-like experiences while falling asleep or waking up (hypnagogic or hypnopompic hallucinations)
    • Having problems keeping up at school and doing daily tasks

    Causes of narcolepsy

    The exact cause of narcolepsy is not always known. In some cases, it can run in families. It may happen without a clear reason.

    Narcolepsy may be linked to changes in a part of the brain called the hypothalamus. It helps control sleep and wake. Some types of narcolepsy involve changes in a brain chemical called hypocretin (also known as orexin). It helps the brain stay awake.

    Children with a type of brain tumor called craniopharyngioma are at risk for narcolepsy. These tumors develop near the hypothalamus. Narcolepsy may develop because of the tumor itself or after treatment, such as surgery.

    Diagnosis of narcolepsy

    The care team will do a patient and family interview or questionnaire, a health history, and a physical exam. They will review your child’s medicines to find out if any of them may cause your child’s sleepiness. They may ask your child to keep a sleep diary to track daytime and nighttime sleep.

    Tests specific to sleep and sleep patterns may include:

    • Blood tests to look for changes in blood counts, hormones, and organ function. 
    • Activity monitor (actigraphy) to track sleep-wake patterns over several days
    • Sleep study (polysomnography) to measure brain, muscle, heart rate, and breathing activity during overnight sleep 
    • Multiple sleep latency test (MSLT) to measure how long it takes your child to fall asleep and when your child enters REM sleep

    In narcolepsy, your child falls asleep quickly and enters REM sleep, a specific part of the normal sleep cycle. People without sleep problems take longer to go into REM sleep. They are less likely to enter REM sleep during daytime naps.

Treatment of excessive daytime sleepiness, hypersomnia, and narcolepsy

Treatment depends on the cause of your child's symptoms. Your care team will recommend the treatment that is best for your child. 

Lifestyle changes

Lifestyle changes can help manage symptoms. These include: 

  • Keeping a consistent sleep routine. 
  • Practicing healthy sleep habits. 
  • Planning short daytime naps, if recommended by your care team.  
  • Getting physical activity during the day.  
  • Avoiding medicines that can cause drowsiness, unless recommended by your care team. 

If you have concerns about your child’s alertness, do not allow your child to do activities that could be dangerous, such as riding a bike, driving, cooking, or swimming.  

Cognitive behavioral therapy (CBT) 

Some children and families may benefit from cognitive behavioral therapy for sleep problems. This type of therapy helps families build healthy sleep habits and manage thoughts or behaviors that may affect sleep. 

CBT may include: 

  • Relaxation skills  
  • Self-soothing skills  
  • Changes to bedtime habits and routines  
  • Ways to manage worry around sleep 

Medicines   

Medicines can help reduce daytime sleepiness, improve alertness, and treat symptoms such as cataplexy (sudden muscle weakness). The choice of medicine depends on your child's age, symptoms, and overall health.  

Medicines that may be used include: 

Other stimulant medicines and certain antidepressants may also be used. Make sure that your child takes the medicine exactly as prescribed. Talk to your care team or pharmacist before making any changes to the dose or timing of the medicine. 

School accommodations   

A child or teen with narcolepsy or other diagnosed sleep disorder may also need special accommodations at school. Families can work with schools to develop a 504 Plan, if appropriate.  

Examples of school accommodations include:  

  • Scheduled naps at school 
  • Later start times 
  • A shortened school day 
  • Extra time on homework or tests 

Tips for healthy sleep

Tips for healthy sleep include: 

  • Know how much sleep your child needs: Children and teens need more sleep than adults. Children with serious illnesses and children with hypersomnia or narcolepsy may need even more sleep. Talk to your care provider about the recommended hours of sleep per day, including naps and nighttime sleep. 
  • Create a comfortable sleep environment: Set up a quiet, cool, and comfortable space just for sleep for your child. Take steps to limit light and noise during the night. 
  • Avoid caffeine and nicotine, especially at night: Make sure your child avoids foods and drinks with caffeine after 4 p.m. or within 6 hours of bedtime. 
  • Exercise regularly: Physical activity during the day can improve sleep at night and can improve daytime alertness. Your child should avoid heavy exercise near bedtime. 
  • Spend time outside: Sunlight or bright light during the day helps your child’s sleep-wake cycle stay on track. 
  • Have a relaxing bedtime routine: Have your child turn off the TV and put away electronic devices. A relaxing bedtime routine may include calm activities like reading, quiet music, or slow breathing. Work with your child on self-soothing strategies.  

Learn more about healthy sleep habits.

Talk to your care team if your child’s sleepiness is new, worsening, or interfering with daily activities. 

Questions to ask your care team

  • Why is my child so sleepy during the day? 
  • What tests will my child need to diagnose hypersomnia or narcolepsy? 
  • What treatments could help my child stay more awake and alert during the day? 
  • Are there changes we can make at home or school to manage my child’s symptoms? 
  • What might help my child sleep better at night?
  • How will this condition affect my child over time? 
  • When should I contact the care team about new or worsening symptoms?

Key points about excessive daytime sleepiness, hypersomnia, and narcolepsy

  • Excessive daytime sleepiness means that your child feels very sleepy during the day, even after getting enough sleep at night.
  • Daytime sleepiness can make it hard for your child to focus, learn, and stay awake during school and daily activities. 
  • Hypersomnia and narcolepsy affect how the brain controls sleep and wakefulness. 
  • Sleep tests, such as an overnight sleep study (polysomnography) and multiple sleep latency test (MSLT), can help diagnose sleep disorders.   
  • Treatment options may include lifestyle changes, medicines, and healthy sleep habits.

Resources for more information on narcolepsy

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The Together by St. Jude™ online resource does not endorse any branded product mentioned in this article.

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Reviewed: July 2026

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