What Is Insufficient Sleep Syndrome?

Sleep Loss Manifests with Sleepiness and Other Symptoms

A man with insufficient sleep syndrome dozes off while reading the newspaper
A man with insufficient sleep syndrome dozes off while reading the newspaper. Jose Luis Pelaez Inc/Blend Images/Getty Images

There are times when too little sleep becomes a big problem. Chronic sleep restriction may lead to profound daytime sleepiness and other effects of sleep deprivation. What is insufficient sleep syndrome? Learn about this condition, when it occurs, the most common associated symptoms, and what can be done about it.

When Does Insufficient Sleep Syndrome Occur?

Insufficient sleep syndrome is defined as a behaviorally induced limitation on total sleep time resulting in inadequate total sleep at night that leads to daily episodes of irrepressible need for sleep or lapses into sleep.

It is not secondary to insomnia but rather reflects a choice to limit sleep. By definition, it occurs most days and lasts at least 3 months. It is a normal response to sleep deprivation, but not everyone’s threshold will be the same.

Sleep needs are largely dependent on age. Children have the highest total sleep need. For example, a 3-year-old needs about 12 hours of sleep. An average adult may need 7 to 9 hours of total sleep. Older adults, beyond the age of 65, may only need 7 to 8 hours of sleep. At an individual level, insufficient sleep syndrome will occur whenever you fail to meet your sleep needs for a prolonged period.

It is also important to recognize that some people are “long sleepers.” If someone requires 9 hours of sleep to feel rested, they will obtain insufficient sleep by getting 8 hours of sleep, even though that would be adequate based on the average for the population.

Many people with insufficient sleep will feel better when they sleep in on the weekends or while on vacation.

Teenagers may be especially susceptible to getting inadequate total sleep time. Their sleep needs are still somewhat longer and they begin to face new social pressures, including demands from friends and schoolwork to stay up later. Budding independence may manifest in a desire to stay up later than their parents.

A tendency towards delayed sleep phase in this population, and required early morning awakenings for school, may further exacerbate the problem.

What Are the Symptoms Associated with Insufficient Sleep Syndrome?

Beyond sleepiness, there are other symptoms that are commonly associated with insufficient sleep syndrome. These additional complaints include:

  • Fatigue
  • Lack of energy
  • Poor concentration or vigilance
  • Reduced attention
  • Restlessness
  • Distractibility
  • Reduced motivation
  • Mood problems
  • Irritability
  • Malaise (feeling unwell)
  • Poor coordination

Beyond these common symptoms, there are a few other more rare occurrences that can occur with chronic sleep deprivation. These range from physical effects to phenomena associated with sleep, including sleep paralysis and hypnagogic hallucinations.

The Diagnosis of Insufficient Sleep Syndrome

Often the diagnosis of insufficient sleep syndrome can be accomplished by simply reflecting on sleep patterns and sleep needs. Consideration of family and work demands is often revealing.

In many cases, it may be helpful to track sleep patterns for at least 2 weeks with sleep logs or actigraphy. This will help to reveal whether sleep needs are being meet and if reduced time in bed is present.

It is generally not necessary to arrange a diagnostic sleep study. It may be used to identify a sleep disorder, such as sleep apnea, narcolepsy, or perioidic limb movements of sleep that may lead to sleep fragmentation. If it were performed, a polysomnogram would show a quick sleep onset and a high (often >90%) sleep efficiency. In the setting of sleep deprivation, a multiple sleep latency test (MSLT) may give inaccurate results.

The Effects and Treatment of Insufficient Sleep Syndrome

When inadequate sleep is obtained to maintain normal alertness and wakefulness, there can be consequences on daytime function. Insufficient sleep may predispose to depression, poor work performance, withdrawal from family and social activities, traffic accidents, and the abuse of stimulants.

The remedy is simple: the time allotted for sleep needs to be extended. This might involve going to bed earlier, turning off the alarm clock, and preserving sufficient time for rest to wake feeling rested. A short trial of sleep extension often provides significant relief and can motivate a long-term commitment to obtaining adequate sleep.

For those who continue to struggle with unrefreshing sleep, speak with a sleep doctor about further options to diagnose your condition.

If you think you are getting too little sleep at night, you probably are. Make some changes to protect your time in bed so that you can obtain sufficient sleep to wake feeling rested and to function at your best during the day.


American Academy of Sleep Medicine. International classification of sleep disorders, 3rd ed. Darien, IL: American Academy of Sleep Medicine, 2014.

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