Sleepiness (Hypersomnia)

It’s not unusual to feel drowsy and tired sometimes, especially when you haven’t gotten enough sleep. Hypersomnia or hypersomnolence is the clinical term for this. The drowsiness can be persistent and severe in some cases, and naps don’t help relieve the issue. This can be a sign of another sleep disorder, an independent condition called idiopathic hypersomnia, or the result of medication side effects, among other causes.

Hypersomnia isn’t life-threatening, but it can certainly impact your quality of life and be associated with serious health conditions. It’s important to understand how this issue impacts your health, what causes it, and how it’s managed.

A woman reaching for the alarm clock

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Symptoms of Hypersomnia

Hypersomnia is primarily defined by either excessive sleepiness or sleeping in excess of 10 hours at night. This leads to:

  • Difficulty waking
  • Confusion and disorientation upon waking
  • Desire to nap throughout the day
  • Anxiety
  • Irritation and restlessness
  • Loss of energy
  • Memory and speech problems
  • Cloudy thinking
  • Loss of appetite
  • Hallucinations

As a result of these symptoms, people with hypersomnia may struggle to stay awake at work or school. You may fall asleep during meals, conversations, or even while driving. This can significantly impact your professional and personal life, drastically impacting your quality of life.

Types of Hypersomnia

Broadly speaking, there are two types of hypersomnia:

  • Primary hypersomnia: This is when the symptoms arise independently of other health conditions. The hypersomnia in these cases may be due to sleep disorders like type 1 and 2 narcolepsy (excessive daytime sleepiness), obstructive sleep apnea, or Kleine-Levin syndrome (a rare sleep disorder normally seen in teenage males). It can also be idiopathic, arising as an independent disorder.
  • Secondary hypersomnia: With secondary hypersomnia, the periods of sleepiness and excessive sleep are caused by medications, certain diseases, or other health conditions, such as hypothyroidism. It can also result from alcohol or drug use or arise due to working overnight shifts.

Causes of Hypersomnia

Many factors can cause periods of drowsiness, sleepiness, and excess sleeping that typifies hypersomnia. The most common causes include:

  • Insufficient sleep
  • Sleep disorders
  • Alcohol or drug use

By far, not getting enough sleep—or having your sleep interrupted—is the leading cause of hypersomnia symptoms. Adults typically need seven to eight hours a night (six hours or less is considered insufficient). According to the National Health Interview Survey, just under 33% of American adults reported getting insufficient sleep in 2017.

Hypersomnia is also a characteristic of sleep disorders and neurologic conditions, including:

  • Narcolepsy is characterized by waves of bouts of sudden sleepiness alongside cataplexy (sudden loss of muscle tone) and muscle weakness.
  • Sleep apnea is caused by interruptions to breathing during sleep due to partial or complete obstruction of the upper airway.
  • Idiopathic hypersomnia is a neurological disorder that causes sleepiness without cataplexy.

Drowsiness throughout the day or sleeping too much at night can also be caused by drinking alcohol or using illicit drugs. In particular, chronic use of such substances and withdrawal from them are associated with decreasing the quantity and quality of sleep.

What Medications Can Cause Hypersomnia?

Periods of hypersomnia can also be side effects of both prescribed and over-the-counter (OTC) medications. Commonly associated classes of drugs include:

  • Antihistamines: Indicated for allergy symptoms, such as congestion, sneezing, and runny nose, antihistamines like Benadryl (diphenhydramine), Zyrtec (cetirizine), Claritin (loratadine), and Allegra (fexofenadine) have drowsiness as a side effect.
  • Antidepressants: Prescribed for depression, selective serotonin reuptake inhibitors (SSRIs) and serotonin norepinephrine reuptake inhibitors (SNRIs) can also cause hypersomnia.
  • Benzodiazepines: Benzodiazepines, such as Xanax (alprazolam), Klonopin (clonazepam), and Librium (chlordiazepoxide) depress the central nervous system (CNS) to treat anxiety, seizures, and other conditions, which can cause excessive sleepiness.  
  • Beta-blockers: Beta-blockers such as Tenormin (atenolol) and Lopressor (metoprolol) lower blood pressure to manage hypertension, heart attack, and other cardiac issues; drowsiness is a common side effect of these drugs.
  • Muscle-relaxers: Indicated to treat muscle spasms, muscle relaxers such as Flexeril (cyclobenzaprine) and Soma (carisoprodol) can also depress the CNS, leading to hypersomnia.
  • Opioids: Prescribed to manage moderate to severe pain, opioid drugs also cause drowsiness as a side effect, along with nausea, vomiting, dizziness, and constipation.

Know What You're Taking

If you’re taking prescribed or over-the-counter (OTC) medications, make sure you understand potential side effects, interactions, and adverse effects. If something you’re taking is making you feel worse or the side effects are affecting your daily life, call your healthcare provider. If you experience alarming symptoms, get emergency help.

Are There Tests to Diagnose the Cause of Hypersomnia?

If you report problematic hypersomnia symptoms, the diagnostic process will focus on isolating their underlying cause. This may involve:

  • Assessing medical history: Alongside basic physical evaluation, the first step involves assessing your symptoms, medical history, medications, and any family history of medical issues. You may be asked to take questionnaires about your condition, such as the Epworth Sleepiness Scale (ESS).
  • Electroencephalogram (EEG): EEG is a noninvasive test that records the activity of your brain waves. Sleep disorders are characterized by specific changes to their patterns of activity.  
  • Polysomnogram: An overnight sleep study, or polysomnogram, involves spending the night in a clinic while your brain waves, breathing, and movement are monitored.  
  • Multiple sleep latency test: In another kind of sleep study, the multiple sleep latency test, you’re asked to try to take a nap every two hours during waking hours while being monitored with video and sensors. Providers measure how fast you’re falling asleep and how quickly you reach rapid eye moment (REM) sleep to differentiate between different types of sleeping disorders.    
  • Clinical testing: Various health factors, such as underactive thyroid (hypothyroidism) or other issues, can also cause hypersomnia. You may need to have samples of urine or blood clinically evaluated.
  • Imaging: Computerized tomography (CT), which can provide a three-dimensional image of the brain, may also be used if a neurological cause is suspected. This involves the use of multiple X-rays of the head. 

How to Treat Hypersomnia

A range of approaches are used to manage hypersomnia, and the course of treatment often depends on the underlying cause of the symptoms. For many cases, certain prescribed medications can help, including:

  • Stimulants: Drugs that stimulate the CNS, such as Ritalin (methylphenidate), Dexedrine (dextroamphetamine), and Adderall (amphetamine), may be prescribed to manage idiopathic hypersomnia or cases related to sleeping disorders.
  • Wakefulness-promoting agents: A more recent class of drugs that manage drowsiness are wakefulness-promoting agents such as Provigil (modafinil) and Nuvigil (armodafinil).  
  • Emerging therapies: Some other drugs have been approved for use or have been shown to help, including Xyrem (sodium oxybate), some antibiotics such as clarithromycin, and a gamma-aminobutyric acid (GABA) receptor agonist called Flumazenil. These are generally considered only if others aren’t yielding results.   
  • Sleeping pills: When the hypersomnia is due to insufficient sleep, you may be prescribed sleep medications such as Lunesta (eszopiclone), Ambien (zolpidem), and others, typically for a short time.

Changing Medication

If the hypersomnia is associated with medications you’re taking, your prescription may need to be changed. Talk to your healthcare provider before making any changes or stopping any medication. Don't make changes without doing so.

Especially when the hypersomnia is associated with other sleep disorders, additional therapies may be effective, especially alongside other treatments:

Lifestyle Changes

Making changes to your sleeping behavior and lifestyle to promote adequate and healthy sleep is critical in managing hypersomnia. This may involve:

  • Avoiding alcohol, tobacco, and illicit drugs
  • Avoiding caffeine or large meals before bedtime
  • Going to bed and waking up at consistent hours
  • Making your bed a no screen or work zone
  • Creating a relaxing routine before going to bed
  • Getting regular exercise

When to See a Healthcare Provider

While excessive drowsiness may not be fatal, it can significantly impact your work, home, and social life. It’s worth calling your healthcare provider if:

  • You consistently have trouble falling or staying asleep.
  • Your hypersomnia may be a side effect of a medication.
  • Your symptoms are consistent and disrupting your daily life.
  • You never feel refreshed after sleeping.

Additionally, consider treatment if you work overnight shifts, fall asleep while driving, or hypersomnia is significantly impacting your daily life.


Hypersomnia is the clinical term for excessive sleepiness throughout the day or sleeping excessively at night. It’s commonly caused by sleeping disruptions, sleep disorders, and alcohol and drug use, though it can also be the side effect of medications. People with hypersomnia find relief by following their healthcare providers’ recommendations, taking certain medications, and making meaningful lifestyle changes.   

A Word From Verywell

Hypersomnia can significantly impact your day-to-day life, making it difficult to drive, stay awake at work or school, and complete your daily tasks of living. While some people just need a little more sleep than others, excessive sleepiness isn't something you should have to endure. If this sounds like you, talk to your primary care provider. They can help determine what is causing your symptoms.

Frequently Asked Questions

  • What causes excessive sleepiness?

    Excessive sleepiness (hypersomnia) is most commonly caused by interrupted or insufficient sleep. However, it can also arise due to other sleeping disorders, such as narcolepsy and sleep apnea, or arise independently.

    Hypersomnia can be a side effect of certain medications and is associated with alcohol and illicit drug use. Anxiety and depression are among mental health conditions that may cause these symptoms, as can hypothyroidism, multiple sclerosis, and others.

  • What can I do at home to help with sleep?

    You can do a lot at home to make sure you’re getting good quality and sufficient sleep. Lifestyle changes that can help include going to bed and waking up at consistent times, relaxing before bedtime, and keeping your bed free of devices or screens. Additionally, getting enough exercise, keeping a good diet, and steering clear of alcohol and tobacco can help. Avoid caffeine or large meals late at night.

  • What should I do if medications are causing my hypersomnia?

    A wide range of prescribed drugs can cause excessive sleepiness, including antihistamines, antidepressants, and beta-blockers. If you think your hypersomnia is due to a medication, call your healthcare provider before making any changes to your dosage. It’s unsafe to stop some medications abruptly, and you may need others to transition to. 

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Additional Reading

By Mark Gurarie
Mark Gurarie is a freelance writer, editor, and adjunct lecturer of writing composition at George Washington University.