What Are the Side Effects of Sleep Deprivation?

Errors, Accidents, Poor Decisions, and Pain Intolerance May Result

Tired man driving car
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It is common to not get enough sleep. Whether you stay up too late or have to get up too early, you may find yourself getting less sleep than you need. What are the consequences of this sleep deprivation? There are clear symptoms and even physical effects of sleep deprivation, but you may be surprised to learn about some of the other potential side effects from injuries to errors to pain.

Sleep deprivation is defined as getting less sleep than your body needs and the threshold may be different for different people.

If you need 10 hours of sleep to feel rested, you may become sleep deprived by only sleeping 8 hours per night. It is also clear that when our sleep becomes fragmented this can also undermine its quality. This may occur in many sleep disorders, including restless legs syndrome and sleep apnea. Sometimes we fragment our own sleep by dividing our sleep periods into shorter stretches. No matter the cause, the consequences can be real.

The single biggest complaint from a lack of shuteye is sleepiness and it speaks to an overall decreased ability to think clearly. Our thinking becomes muddled and our capacity for decisions and judgments may be compromised. There may be difficulties with learning and concentration. Studies demonstrate impairments in immediate recall and short-term memory with sleep deprivation. This may lead to errors or on the job, including an increased risk for accidents. In fact, the risk for injuries in general has been correlated with the degree of sleep deprivation.

Sleep Deprivation Endangers Drivers

Not only are we potentially subject to accidents at work, but studies have shown that we are at a greater risk for traffic accidents. Perhaps some individuals fall asleep straight away while driving and crash, but many others simply have a compromised ability to drive.

Sleep deprivation affects our response time and hand-eye coordination.

In fact, research using driving simulators suggests that driving while sleep deprived may be as dangerous as driving while intoxicated. In one study, sleep deprived subjects drove off the road every 5 minutes, which was correlated to a blood alcohol level of 0.08%. Sleep deprivation disrupts how quick we respond to stimuli and our ability to track things visually, which also lead to dangerous driving.

Fatal accidents have led to strict work hour regulations in long-haul truck driving as well as in the passenger transportation industries such as the airlines.

Impaired Judgment, Pain Tolerance May Cause Varied Troubles

Sleep deprivation may not only put you in physical harm; it might undermine your interpersonal relationships, judgment, and sense of well-being. As alluded to above, sleep deprivation affects our judgment. This relates to problems in the foreward part of the brain called the frontal lobe. The frontal lobe is critical for higher level cognitive processes called executive functions.

Much like a high-powered executive in a business, the frontal lobe is involved in critical thinking. It helps you to make important judgments. It aids our social interactions. When it is not working well, such as may occur in sleep deprivation, problems develop. You are less able to make complicated decisions or consider hypothetical outcomes. You may be subject to increased personal conflicts. You may even make poor choices.

Finally, there is an interesting relationship between sleep deprivation and our overall conception of our personal health. People who do not sleep well are more likely to have health complaints. Research demonstrates that those who are sleep deprived have a decreased threshold for pain. This increased pain sensitivity appears to relate to a loss of deep (or slow wave) sleep. If our sleep is fragmented, no matter the cause, we are subject to the same nagging pain complaints.

Sleep deprivation clearly has important effects on the quality of our life. Although it may put us at immediate risk in the setting of dangerous driving, it can also undermine our ability to make proper decisions and interact appropriately with others. It also may lead to a decreased tolerance of pain. For all of these reasons, and more, it is imperative that we get that quantity and quality of sleep that we so desperately need.


Arnedt, JT et al. "How do prolonged wakefulness and alcohol compare in the decrements they produce on a simulated driving task?" Accid Anal Prev 2001;33:337-344.

Kryger, MH et al. "Principles and Practice of Sleep Medicine." Elsevier, 5th edition, pp. 54-75.

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