What Are the Physical Effects of Sleep Deprivation on the Body?

From Hormonal Changes to Weight Gain, Major Problems May Result

Physical effects of sleep deprivation include vital sign and hormone changes
Physical effects of sleep deprivation include vital sign and hormone changes. noa images/Photodisc/Getty Images

Sleep deprivation is common for people in many societies, seemingly with no long-term damages, but is this true? Does sleep deprivation have lasting physical effects on the body? Learn about what some of the impacts on your health are, ranging from nervous system, vital sign, and hormonal changes as well as weight gain.

The Physical Effects of Sleep Deprivation

Sleep deprivation occurs any time that you get less sleep than your body needs.

The degree of sleep deprivation can range from total acute sleep loss to chronic deprivation due to a reduction in the total sleep time. This can occur over one night or stretch over weeks, months, or even years. If someone requires 9 hours of sleep to feel rested, it is possible to become sleep deprived by getting 8 hours of sleep.

Most of the physical side effects from sleep deprivation are relatively minor and, thankfully, easily reversible. And the cure? Get some sleep. If you do not sleep enough, you may be faced with myriad consequences, including:

  • Neurologic Effects of Sleep Deprivation

Sleep deprivation mimics the effects of drinking alcohol - you may experience slurred speech and uncontrolled reflexive movements of the eye called nystagmus.

You may also develop a slight shakiness or tremor in your hands. Some people even have a more pronounced droopiness in their eyelids, called ptosis.

Various other neurological reflexes can change in sleep deprivation. These are unlikely to causes symptoms you would notice. However, if your doctor were to test them, you may have sluggish corneal reflexes, a hyperactive gag reflex, and hyperactive deep tendon reflexes.

In addition, you may have a reduced threshold for seizures.

As a result, people with epilepsy are at greater risk for seizures when they're sleep deprived.

One thing that you may notice right away is an increased sensitivity to pain. Studies have shown our sensitivity to heat and pressure pain is especially enhanced when we don’t sleep enough. Also, there is reported to be an increased sensitivity to pain in our esophagus, as might occur in the setting of nighttime heartburn or gastroesophageal reflux disease (GERD).

  • Vital Sign Changes in Sleep Deprivation

Research studies have demonstrated that sleep deprivation may cause subtle changes in your vital signs. Vital signs are important physiological markers that are often tracked as part of a general health assessment. These include:

  • Body temperature
  • Blood pressure
  • Heart rate
  • Breathing rate

As an example, sleep deprivation may cause a small overall decrease in your body temperature. Changes in the other vital signs are relatively mild based on various studies. Seep-deprived people, when they do sleep, tend to have longer and more frequent pauses in their breathing called apnea.

  • Hormonal Changes in Sleep Deprivation

Sleep deprivation can have significant and important effects on the secretion of hormones from endocrine glands, especially those that follow a circadian pattern. A classic example includes the effect of sleep loss or disruption in children and the impact on growth. Growth hormone is secreted during slow-wave sleep, which is more common in the early part of the night in children. When this sleep is disrupted, either through inadequate sleep or from disorders such as sleep apnea, the amount of growth hormone released is compromised. As a result, children may not reach their full growth potential, becoming shorter than they otherwise would have been.

Sleep deprivation also seems to affect the activity of the thyroid gland. It is thought that the increased energy needs while staying awake for too long demand more work from the thyroid.

Fortunately, studies also suggest that many other hormones (including sex hormones) do not seem to be affected by sleep deprivation, including:

  • Cortisol
  • Adrenaline
  • Catecholamine
  • Luteinizing Hormone
  • Follicle-Stimulating Hormone
  • Testosterone
  • Progesterone

This may provide you some relief, but there is still a risk of major health effects from not getting enough sleep.

  • Major Health Effects of Sleep Deprivation - Including Death

Ultimately, the concern of these various physical effects of sleep deprivation is the role it may have in our overall health. Indeed, sleep deprivation may negatively affect our health and may even lead to death in extreme situations.

Moreover, chronic sleep deprivation may adversely impact our metabolism, leading to impaired glucose tolerance (a risk for diabetes) and weight gain. In addition, there seems to be some evidence that sleep deprivation undermines our immune function, putting us at risk for frequent illness.

For all of these reasons, is it is important that we place a premium on our sleep and obtain the amount of rest that our bodies need.


Kryger, MH et al. "Principles and Practice of Sleep Medicine." Elsevier, 5th edition, pp. 502-503.

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