Why Am I Excessively Sleepy? Drowsiness Explained

Medically Reviewed By Thomas Johnson, PA-C

Common causes of drowsiness include sleep disorders, depression, and certain medications. Drowsiness is also called “somnolence” or “excessive sleepiness.” Sleep disorders are a common cause of drowsiness. These include Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source sleep apnea, insomnia, and narcolepsy. Sleep apnea is a condition in which you temporarily stop breathing while asleep.

Keep reading to learn more about the causes of drowsiness and how to treat and prevent it.

What causes drowsiness?

a woman and her cat are on a bed
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Certain conditions and medications are known to cause sleepiness. Conditions include depression, anxiety, and sleep disorders. Medications include sedatives and tranquilizers, pain medications, and antiallergy medications, such as antihistamines.

Common causes of drowsiness

Depression, stress, and grief are also associated with compromised sleep, partly due to their link with inflammation. Treating or minimizing these conditions can greatly improve the ability to fall asleep and stay asleep.

Certain medications for these conditions are also known to cause somnolence. These include sedatives and tranquilizers, pain medications, and allergy medications, such as antihistamines.

Drowsiness can result from common situations or conditions that affect sleep, such as:

  • depression
  • grief
  • irregular work schedule such as shift work (circadian rhythm sleep disorder)
  • stress
  • travel across time zones (jetlag)
  • insufficient sleep hours

Sleep disorders that cause drowsiness

Sleep-wake disorders are a common cause of drowsiness. These include Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source many conditions, including sleep apnea, insomnia, and narcolepsy. 

  • Sleep apnea is when you stop breathing Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source while asleep, often several times a night. The deprivation of oxygen and constant sleep disruption lead to daytime sleepiness, lethargy, and fatigue.
  • Narcolepsy is characterized by daytime sleep episodes. Insomnia is the perception that you’re not getting enough sleep or that the sleep you are getting is inadequate.
  • Circadian rhythm sleep disorder frequently occurs in shift workers with fluctuating schedules. Drowsiness can impact family life, job performance, and workplace safety.

Medications that cause drowsiness

Drowsiness can also be the result of medications, including:

  • anticonvulsants, which can treat epilepsy and seizures
  • antidepressants
  • antiemetics, which can help treat nausea
  • antihistamines or other allergy medications
  • sedatives or tranquilizers

Serious or life threatening causes of drowsiness

The sudden onset of drowsiness can mean a life threatening condition, especially if related to a head injury, exposure to extreme cold, or medication overdose.

Seek immediate medical care (call 911) if you or someone you are with has experienced a head injury, have taken too much medication or a new medication, or are experiencing cold exposure (hypothermia) and become extremely drowsy.

Sometimes, drowsiness may be a symptom of a serious or life threatening condition, such as:

What other symptoms might occur with drowsiness?

Drowsiness may accompany other symptoms, which vary depending on the underlying disease, disorder, or condition.

Related symptoms that may occur along with drowsiness

Drowsiness may accompany other related symptoms, including:

Learn more about the symptoms of sleep apnea.

Other symptoms that may occur with drowsiness

Drowsiness may accompany symptoms related to other body systems, including:

When should you seek emergency care?

In some cases, drowsiness may be a symptom of a life threatening condition. Seek immediate medical care (call 911) if you or someone you are with has any of these life threatening symptoms:

Questions for diagnosing the cause of drowsiness

To diagnose your condition, your doctor or licensed healthcare practitioner will ask you several questions related to your drowsiness, including:

  • How long has this drowsiness been occurring?
  • Do you have other symptoms?
  • Have you recently started taking medication?
  • How much sleep do you typically get?
  • What is your work schedule like?
  • Do you awake from sleep frequently? Have you been told that you snore?
  • Do you fall asleep often, especially in front of the computer, after lunch, or watching TV?
  • Do you wake up feeling lively and energized?
  • Do you feel depressed or anxious, or have you recently suffered a loss?

Learn why to see a specialist for sleep apnea.

What are the potential complications of drowsiness?

Because drowsiness can be due to serious diseases, a delay in seeking treatment can result in complications and permanent damage. After the underlying cause is diagnosed, follow the treatment plan that you and your healthcare professional designed specifically for you to reduce the risk of potential complications, including Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source :

  • depression
  • heart disease
  • inability to perform daily tasks
  • poor quality of life

How do doctors treat drowsiness?

Treatment for drowsiness will depend on its cause:

  • Medications: If a medication is causing your drowsiness, speak with a doctor about changing the medication and finding the correct treatment plan for your symptoms.
  • Depression, grief, or stress: A doctor may recommend talking therapy, such as cognitive behavioral therapy, or certain medication to help you treat this underlying cause of drowsiness.
  • Sleep disorders: Resolving underlying causes, such as heart disease or weight management, might help Trusted Source Centers for Disease Control and Prevention (CDC) Governmental authority Go to source with sleep disorders. Also, nasal continuous positive airway pressure (CPAP) may be beneficial. Stimulant medications can help treat narcolepsy. A combination of sedative-hypnotic or sedating antidepressant medications and behavioral techniques can help people with insomnia.

Learn more about treatment options for depression.

How is drowsiness prevented?

Sometimes, drowsiness is the result of an underlying medical condition or medication. Talk with your healthcare team about finding the best treatment for you.

Here are some tips for avoiding drowsiness:

  • Avoid alcohol consumption if you drink.
  • Establish a regular sleep routine where possible.
  • Maintain a moderate weight.
  • Avoid relying on caffeine when you feel tired.
  • Avoid doing anything that could cause an accident, such as driving or operating heavy machinery when you’re feeling drowsy. If drowsiness begins while driving, pull over to a safe spot and take a 20-minute break.

Learn our 10 sleeping tips.

Frequently asked questions about drowsiness

Here are some commonly asked questions about drowsiness.

Does drowsiness mean sleep?

Drowsiness refers Trusted Source PubMed Central Highly respected database from the National Institutes of Health Go to source to feeling sleepy or tired or unable to keep your eyes open. Drowsiness, also called “excess sleepiness” or “somnolence,” can be accompanied by lethargy, weakness, and lack of mental agility. While most people feel drowsy at some point, persistent sleepiness or fatigue, especially at inappropriate times, can indicate a sleep disorder or other medical problem.

What medicines can make you drowsy?

The following medications may cause drowsiness:

  • antihistamines or other allergy medications
  • antidepressants
  • anticonvulsants (used to treat epilepsy and seizures)
  • antiemetics (used to treat nausea)
  • sedatives or tranquilizers

What drinks help you stay awake?

Some drinks, such as caffeinated beverages or energy drinks, may help you stay awake. However, these are only short fixes, and it can often take up to 30 minutes before you feel their effects. Therefore, they are not a long-term or recommended solution to drowsiness.


Drowsiness is also called “excessive sleepiness.” A person with drowsiness may experience lethargy, weakness, and lack of mental agility.

Common causes of drowsiness include sleep disorders, such as sleep apnea, insomnia, and narcolepsy. Other causes include depression, stress, grief, or altered sleep routines. Some medications can also cause drowsiness.

The treatment of drowsiness involves addressing underlying causes.

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  1. Bazil, et al. (2013). Sleep and drowsiness and memory. https://www.epilepsy.com/complications-risks/sleep/drowsiness-memory
  2. Drowsiness. (n.d.). https://www.ncbi.nlm.nih.gov/medgen/4390
  3. Drowsy driving. (n.d.). https://www.nhtsa.gov/risky-driving/drowsy-driving
  4. Drowsy driving and automobile crashes. (n.d.). https://one.nhtsa.gov/people/injury/drowsy_driving1/Drowsy.html
  5. Ikpeze, T. (2022). https://www.sleepapnea.org/what-is-sleep-apnea/
  6. Key sleep disorders – sleep and sleep disorders. (2022). https://www.cdc.gov/sleep/about_sleep/key_disorders.html
  7. Lee, C.-H., et al. (2019). The role of inflammation in depression and fatigue. https://www.frontiersin.org/articles/10.3389/fimmu.2019.01696/full
  8. Wang, H., et al. (2019). Genome-wide association analysis of self-reported daytime sleepiness identifies 42 loci that suggest biological subtypes. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6692391/
  9. Tips to prevent drowsy driving. (n.d.). https://trafficsafety.ny.gov/tips-prevent-drowsy-driving
  10. Zhang, D., et al. (2021). Excessive daytime sleepiness in depression and obstructive sleep apnea: More than just an overlapping symptom. https://www.frontiersin.org/articles/10.3389/fpsyt.2021.710435/full

Medical Reviewer: Thomas Johnson, PA-C
Last Review Date: 2022 Oct 31
View All Symptoms and Conditions Articles
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