The 5 Stages of Sleep Deprivation and How they Affect your Body and Mind.

Discover the five stages of sleep deprivation and their profound impacts on the body. Learn why quality sleep is essential for your health.


Losing sleep is no joke, but if you have ever dealt with sleep deprivation, you know how vital sleep is to your overall health. Sleep deprivation is often defined as getting less than seven hours of sleep, which is the minimum most need to have a productive, balanced day. However, some people go days without sleep, experiencing all five stages of sleep deprivation while causing both mental and physical harm to their bodies. 

 In this article, we’ll uncover the five stages of sleep deprivation, how they affect your mind and body, and why losing sleep can be harmful, even over a matter of days. By the end of this, you’ll see the importance of sleep, but you’ll also understand sleep deprivation even more than you did before. 

The 5 Stages of Sleep Deprivation

Stage 1: The First 24 Hours

The first stage of sleep deprivation for severe cases is when you first go without sleep for a whole day. That means over an entire 24-hour period, you fail to get any sleep, and you are awake the entire time. During this initial day of being sleep-deprived, you’ll immediately notice your body reacting to the situation. You may even feel like you are under the influence of alcohol.

Studies have shown that if you go without sleep for a full day, it is nearly the same as having a blood alcohol concentration (BAC) of .10%, which is enough for you to feel out of it and unable to do ordinary tasks like driving. You may also feel drowsy, angry, stressed, or even have puffy eyes or tremors. It is also common for you to notice some memory challenges at this stage. Even after one full day without sleep, studies show that your learning and memory can be hindered—sometimes permanently (Source: National Library of Medicine). 

Stage 2: 36 Hours without Sleep

The next stage of sleep deprivation is when you go 36 hours without getting a single minute of sleep. At this stage, you may find that you have an increased sense of irritability and sleepiness, and you may even have trouble thinking or even begin to get headaches. Something else you may notice is your body continues to dip in and out of sleep, usually every 30 seconds or so. These events are called microsleeps, and you might not even notice this happening to you!

As you continue to go without sleep, you may also notice even more pronounced impairment when it comes to your mental performance. If you’re sitting in class or trying to learn something new without sleeping for over a day, you will struggle, just like you’ll struggle with making sound decisions, reacting quickly, and even avoiding errors. Ultimately, this is because your working memory is impaired after you go without sleep for 36 hours straight.   

Physically, you’ll also notice a considerable difference because of your lack of sleep. Many people feel more hungry, experience more inflammation, and even have extreme fatigue on top of an impaired immune system (Source: International Journal of Tryptophan Research). Because sleep helps with inflammation, the more you lack sleep, the less your body can prevent inflammation, which can be present in your physical body through bloating or even headaches. However, your experience with sleep deprivation grows even worse by the third stage. 

Stage 3: Two Fully Awake Days

In this stage, you have been awake for 48 hours, which leads to a number of unique and debilitating symptoms. Many people even report hallucinating when they get to the stage, often due to the fact that they are so sleep-deprived that they cannot make sense of what's in front of them. On top of this, you may even find yourself struggling to communicate with others, even feeling a sense of depersonalization.

Depersonalization refers to a detachment from yourself, where you feel like you're watching things happen without really taking control of your reality. This can be a very unsettling experience, especially on top of the other symptoms that you may struggle with, including anxiety, stress, increased fatigue, and even irritation. 

If you’re an athlete, the need for sleep is even greater. When athletes are sleep-deprived, their muscle recovery is prolonged, as it normally takes at least two full days to recover from a workout. However, we haven’t even discussed the most severe phases: stage 4 and stage 5. 

Stage 4: Three Days of No Rest

The most severe symptoms of sleep deprivation come after 72 hours of no sleep at all. Imagine all the symptoms that we've previously discussed becoming even more intense to the point where you can't even tell what is real and what is not anymore. Your urge to sleep will become even worse, and you'll have even more frequent and longer microsleeps, largely because your body desires sleep so much and requires it to recover from the stress that it's been under.

If you reach this stage of sleep deprivation, you may also experience delusional, disordered thinking, becoming even more depersonalized and detached from yourself. This is often when people are unable to remember what's going on or think critically, and it can be a very dangerous position to be in, regardless of your situation.

Stage 5: What Happens After 96 Hours? 

The final stage, stage 5, is when you've been awake for four days, and you can only imagine how severe the symptoms have become at this point. At this time, you'll likely have a very severely distorted perception of your reality, and you'll want to sleep so badly that you'll probably end up falling asleep without meaning to. You may even experience psychosis because you can't decide what reality looks like and can't decipher what is going on around you, but fortunately, even if you reach this stage, you can always recover if you just lie down to rest.

For those that reach this stage of sleep deprivation, you may find that you can actually lose memory and experience memory decline over time. You also, especially if you engage in long-term sleep deprivation throughout your lifetime, can increase your likelihood of dying from cardiovascular diseases, which can be very harmful to your overall health (Source: GeroScience). Evidently, those who reach this stage of sleep deprivation can experience long-term challenges, but the hope is that we all do our best to improve our sleep and ensure we are getting enough rest. 

The Importance of Proper Sleep

Sleep deprivation is no joke, and hopefully, this article sheds some light on the stages of sleep deprivation and how harmful long-term sleep loss can be. From the initial disorientation akin to alcohol impairment to the severe cognitive and physical breakdowns after days without rest, sleep deprivation underscores the non-negotiable necessity of sleep for our health.


Written by

Marie Soukup

Marie Soukup is a seasoned copywriter, editor, and Integrative Nutrition Health Coach with a certificate from the Institute of Integrative Nutrition (IIN). With five years of experience working with brands across diverse industries, Marie is passionate about holistic health and crafting compelling content.

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