Skip to main content

Verified by Psychology Today

Hypersomnolence is marked by excessive and chronic daytime sleepiness. People who suffer this disorder do not enjoy restorative nighttime sleep, though some individuals sleep up to seven hours a night.

These sufferers nap throughout the day—at work, sitting down at dinner, and even at social events. The sleepiness is gradual and not normally experienced as an onslaught. The napping does not give the sufferer relief.

This disorder is common in both males and females, and onset age is 17 to 24. About 1 percent of the population experiences symptoms of hypersomnolence, particularly the prolonged impairment of alertness upon waking (sleep drunkenness).

This disorder is also associated with depressive disorders, bipolar disorder, substance-related disorders, Alzheimer's disease, Parkinson's disease, and multiple system atrophy.


These sufferers find it difficult to wake from sleep, find it hard to move, feel confused and sometimes also irritable. It can take a person minutes to hours to awaken fully. These people may even sleep as much as nine hours a day, without feeling refreshed. To receive a diagnosis of hypersomnolence disorder, the individual must have the following symptoms at least three times per week.

Signs and symptoms of hypersomnolence, as cataloged by the DSM-5:

  • Excessive sleepiness, despite getting at least seven hours of sleep per night
  • Recurrent daytime naps or lapses into sleep during the same day
  • Non-restorative nighttime sleep that lasts for more than seven hours
  • Difficulty fully waking from a long sleep and feelings of confusion or disorientation that may last minutes or hours
  • Increased sleep time (up to 14 to 18 hours per day)
  • Significant distress or impairment in functioning as a result of excessive sleep

If symptoms last for less than one month, hypersomnolence disorder is considered to be acute. If symptoms last for one to three months, the condition is considered subacute. If symptoms last for more than three months, the condition is considered persistent.

Other possible symptoms:

  • Anxiety
  • Increased irritation
  • Decreased energy
  • Restlessness
  • Slow thinking
  • Slow speech
  • Loss of appetite
  • Hallucinations
  • Difficulties with memory
  • Inability to function at work, home, or socially

To be diagnosed with hypersomnolence, excessive sleepiness cannot be due to the physiological effects of a substance or a general medical condition.

article continues after advertisement


Drug or alcohol abuse can cause hypersomnolence. Other sleep disorders can also cause it, including narcolepsy or sleep apnea, or dysfunction of the autonomic nervous system. Physical problems, such as a tumor, head trauma, or injury to the central nervous system can also cause the condition. In addition, medications or medication withdrawal may also cause hypersomnolence. Other possible contributors include medical conditions including multiple sclerosis, depression, encephalitis, epilepsy, or obesity. And some people appear to have a genetic predisposition to hypersomnolence.


Amphetamines, methylphenidate, or modafinil may be prescribed. Other possible drugs for treatment include clonidine, levodopa, bromocriptine, antidepressants, and monoamine oxidase inhibitors (MAOIs). Lifestyle changes may help. A better diet, as well as avoiding social activities or nighttime work that delay bedtime may also help.

See your primary care physician if you:

  • Repeatedly cannot fall asleep at night
  • Perpetually feel tired during the day

Your physician may refer you to a sleep specialist. Sleep disorders can be treated effectively.

American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition
Textbook of Clinical Neurology. 3rd ed.
University of Maryland Medical Pages
Last updated: 02/21/2019