Sleep deprivation is common and widespread. The Centers for Disease Control and Prevention has found that over one in three American adults do not get an adequate amount of sleep.1 If you aren’t sleeping enough for a long time, you may become accustomed to the feeling of sleep deprivation, to the point that you may not even realize you are sleep deprived.2 Being familiar with the signs of sleep deprivation can help you make informed choices about whether you need to get more sleep.
In a busy world with schedules, alarms, and millions of things to keep us up late, it is easy to become sleep deprived without even realizing it. One study found that subjects that did not report any sort of sleep deprivation actually were sleep deprived. This was determined by allowing the subjects to sleep as long as they wanted for over a week. It was found that when given the opportunity, most of the participants slept for a longer period of time than they expected. Observed daily sleep time outside of the study was shorter than the time spent sleeping when other demands were removed. After a few days of sleeping much longer than they were accustomed to, the subjects appeared to catch up on sleep enough to stabilize at a slightly longer sleeping time than they would normally have slept.3
Lack of sleep symptoms include having a shorter temper than normal, loss of or inability to focus, and general fatigue. Some of the more subtle signs of sleep deprivation include reduced immune function, weight gain, and reduced insulin sensitivity.4
Lack of sleep effects can accumulate and grow more and more dire. The mental effects of a night of insomnia or missed sleep are clear. Everyone has felt just how irritable and miserable you can be if you miss too much sleep. Sleep deprivations effects on the brain such sleep deprivation headaches5 that can occur after even only an hour of lost sleep from one night. There is research to indicate that this may be due to the restorative properties of sleep. The brain’s glymphatic system helps not only eliminate metabolic wastes from our brains, but also helps to distribute critical compounds for proper brain function6. Sleep deprivation can negatively affect physical endurance, although short burst physical performance seems unaffected.7
Sleep deprivation over multiple nights can lead to what is termed sleep debt. Different parts of the body require different amounts of uninterrupted rest, and take different amounts of time to recover when sufficient sleep is restored.
The endocrine system, responsible for the secretion of hormones and other signaling chemicals in the body, is harmed by chronic sleep deprivation. Insulin sensitivity and glucose tolerance reduce due to sleep deprivation.8 Unfortunately, these two changes are hallmarks of type II diabetes, and the changes from sleep deprivation may become irreversible.
The unwell feeling of chronic sleep deprivation can begin to feel like your new normal, and in fact, people may not realize they are sleep deprived. There may be lingering grogginess or brain fog throughout the day, and you may find yourself falling asleep at times during which you would like to remain awake.
Sleep deficiency can have a variety of negative effects. People that are sleep deprived become more sensitive to pain and have difficulty regulating their emotions or behavior. Responses to stress or changes may be excessive.
Everyone has natural differences in sleep needs, and daily activities can increase the amount of sleep needed on a given night. This means that there isn’t a set amount of missed sleep that can be used as a tell-tale marker of sleep deprivation. The guide for how much sleep is enough should be based on personal experience. If you know that after a certain period of sound, restful sleep you feel refreshed, then that should be your standard. If you get less than that amount for more than one night, you can end up sleep deprived.
Some short-term effects of mild sleep deprivation may be reversed by allowing yourself to sleep as long as you naturally desire. After one night, you should feel mentally refreshed. However, there is research that indicates the other functions of sleep may require up to nine days to catch up with accumulated sleep debt. Remember, sleep doesn’t just let your mind rest; there are physiological functions that take place while you are sleeping. For example, immune system molecules that modulate inflammation and response to infections accumulate while awake, but drop while sleeping.9 Some of these physiological functions take a while to return to normal after a period of sleep deprivation. This is why it is so important to establish and maintain healthy sleep habits.10
© 2021 American Sleep Association.