While you might sleep for a day or two without hurting yourself or others, it's not a healthy habit. A common misconception about sleep is that we only need it for energy during the day, and that a few cups of strong coffee in the morning can serve you just as well as to rest all night long. This will largely depend on how your body responds to resting this way. Some people can function really well with just 3 hours and actually perform better after sleeping in bursts.
However, many experts still recommend a minimum of 6 hours per night, with 8 being preferable. Some people divide their sleep into an all-day nap schedule, sometimes called polyphasic sleep. With simple, gradual adjustments to your sleep-wake routine, you'll eventually meet your sleep needs every night. However, continuously filling the body with this substance is one of the reasons why so many chronic debilitating diseases are associated with chronic lack of sleep.
In addition to that, sleep recovery after sleep restriction demonstrates that the brain self-regulates in the face of sleep deficiency, invalidating “sleeping tricks”. Sleep is essential to health, and deep sleep is the most important of all to feel rested and stay healthy. If you have to limit your sleep for a few days, you can increase your energy by spending time in sunlight, taking short naps during the day, and exercising lightly. Sleeping five hours (or four, six or seven or, more specifically, any period of time lower than the biological need for sleep) will cause lack of sleep, leading to both immediate and long-term side effects.
Many people say that polyphasic sleep allows you to sleep more efficiently and achieve the same amount of rest in fewer hours. What many people don't realize is that the immediate effects of lack of sleep far outweigh the subtle signs that you're not functioning or feeling your best. Only you will know what your body can handle and if any of the sleep structures are adequate for your various needs. Three consecutive sleepless nights will have a big impact on your body and mind, including your mental health.
In addition, research indicates that restricting sleep for one night, or several consecutive nights, preserves slow-wave sleep (stage N) and reduces sleep in stages N1, N2 and REM. Even if you only feel a little tired during the day, it's actually an indication that your body is already suffering from lack of sleep. In fact, sleeping one hour less for 10 consecutive nights will cause your brain to deteriorate as much as it would if you had been awake for a full 24 hours, although it's quite possible that you don't feel that way.
