Are You Oversleeping? 10 Causes of Excessive Sleep

by | Last updated Oct 5, 2021

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Most adults need seven to nine hours of quality sleep per night. So what’s another hour or two? Getting more than nine hours of sleep isn’t bad, right? Wrong. It may be a sign of something more serious. So how much sleep is too much sleep? 

Well, the “right” number of hours an individual should sleep is personal and will vary, but anything over nine hours is generally considered excessive sleep for an adult. There are several reasons you may be getting excessive sleep. We’re naming 10 causes of excessive sleep below. 

If you’ve ever asked yourself “why am I sleeping so much?” or “why am I always tired?” or  you know someone who is experiencing excessive sleepiness and is guilty of snoozing throughout the day or sleeping long every night, continue reading to discover reasons why and learn what you can do about it. 

Is Excessive Sleepiness Common?

If you’re wondering why you’re so sleepy, you’re not alone. Excessive Sleepiness is common, in fact, 40% of people exhibit occasional symptoms of hypersomnia. 

Hypersomnia is the clinical term for excessive sleepiness and excessive sleeping. The condition is marked by excessive daytime sleepiness or an above-average amount of time sleeping (usually way beyond the recommended 7-9 hours). Many with hypersomnia can fall asleep anywhere or at any time which is a bit awkward at work but a lot more troublesome while driving. 

Should I Be Concerned if I Get Excessive Sleep?

As you know, a good night’s sleep is critical and essential for health. Yet not all instances of excessive sleepiness are cause for worry. Occasional feelings of exhaustion leading to a night or two of excessive sleep are commonplace.  Yet, if the feelings of exhaustion are interfering with the quality of your life, you should consider making specific lifestyle changes, or getting tested for certain sleep disorders. . 

That’s because sleep disorders can be a potential cause of hypersomnia and impact how you sleep, affecting your overall health, safety, and quality of life. It’s common to associate sleep disorders with getting too little sleep, yet sleep apnea and narcolepsy can actually cause hypersomnia or excessive tiredness.  Hypersomnia poses serious health risks and is linked to several medical problems such as diabetes, heart disease, and death. 

If you’re getting excessive sleep read through the factors that may be contributing to your excessive sleepiness. Some may not be cause for concern and represent temporary sleep behavior alterations, others are more serious.  

Causes of Excessive Sleep and Fatigue

People with hypersomnia suffer from extreme sleepiness during the day, and unusually long periods of sleep during the night. However, a range of factors can cause excessive sleepiness. View ten reasons why you could be sleeping too much:

1. Sleep Disorders

You could suffer from narcolepsy or sleep apnea. Sleep apnea (OSA) is especially common and if you have undiagnosed OSA you experience airway blockages which cause repeated interruptions to your sleep throughout the night. You won’t likely remember these blockages waking you up, but you’re waking up most or all mornings feeling tired and irritable, and feeling anxious and fatigued during the day.

2. Autonomic Dysfunctions

There could be a dysfunction of the autonomic nervous system. Some sleep disorders, such as obstructive sleep apnea and hypoventilation syndrome, are associated with clinically relevant autonomic dysfunctions involving cardiovascular and respiratory control.

3. Drug and Alcohol Abuse

Drinking alcohol blocks REM sleep, which is the period when your body restores itself. Ongoing use has many health repercussions, including poor quality of sleep.

4. Insufficient Sleep Due to Change

A change in work schedule, a new responsibility after school, or a recent issue with a relationship gives adults and young adults reason to miss winks or sleep poorly. 

5. Physical Injuries or Issues

Physical problems such as a tumor, head trauma, or injury to the central nervous system. Sleep disturbances occur in 30-70% of those with traumatic brain injuries. Insomnia, fatigue, and sleepiness are the most common complaints after a head injury.

6. Mental Well-Being

Depression, anxiety, and mental states in general can keep a person awake at night, making them prone to sleepiness during the day.

7. Medical Conditions

Asthma, chronic pain, reflux, psychiatric illnesses, and other painful conditions can negatively impact sleep patterns.

8. Medications

Caffeine, sleeping pills, and antihistamines can disrupt sleep patterns. Caffeine blocks brain receptors from absorbing adenosine, a substance in your body that facilitates sleep. Caffeine has a half life of three to five hours, yet it can stay in your system for long after.

9. Time Zone

Jet lag is an example and type of circadian rhythm sleep disorder. When changing time zones, our bodies are not immediately adapted to that environment’s 24-hour light and darkness cycle. Even a few hours can throw a person’s internal clock out of line, creating sleep-wake issues.

10. Environment Factors

Uncomfortable mattress, too much heat or cold, or noise. Keeping your sleeping quarters 65 degrees is considered optimal. Your body gives off warmth right around the time you get to bed, and the body cools down during sleep. Any room temperature that disrupts comfort or the ability for the body to cool down interferes with sleep.

These are a few causes of excessive daytime sleepiness, but the list goes on. You may be experiencing the effects of these factors without realizing they’re the cause. Identifying the causes of excessive sleepiness may involve an in-depth investigation into lifestyle habits, physical health, emotional and/or mental states.

Sleep Disorder Diagnosis and Treatment

Sleep disorders come in many forms, and have a negative impact on your daily life. If you suspect a sleep disorder or combination of sleep disorders, it’s best to seek a diagnosis and possible treatment at a sleep center with qualified professionals. 

Sleep Centers of Middle Tennessee is leading the way to better sleep care; we are researchers who continuously strive to understand better sleep and the challenges that our clients face. We’re leaders in the field of sleep medicine and have a team of experts who are qualified and dedicated to helping people get good sleep.

We have three convenient sleep center locations in MURFREESBORO, FRANKLIN, and CLARKSVILLE, Tennessee. If you suspect your excessive sleepiness is related to obstructive sleep apnea, we can help you get tested in the comfort of your home through our OSAinHome program which provides telemedicine visits for residents outside of Middle Tennessee.

Get in contact with us now because everyone deserves to wake and feel well rested throughout the day.






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Fink, Anne M et al. “Autonomic regulation during sleep and wakefulness: a review with implications for defining the pathophysiology of neurological disorders.” Clinical autonomic research : official journal of the Clinical Autonomic Research Society vol. 28,6 (2018): 509-518. doi:10.1007/s10286-018-0560-9 <>

Viola-Saltzman, M., & Watson, N. F. (2012). Traumatic brain injury and sleep disorders. Neurologic clinics, 30(4), 1299–1312. <>

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