How Long Can You Go Without Sleep – The Shocking Facts!

Have you ever wondered how long you can go without sleep? This ultimate guide breaks down how long you can go without sleep and how it affects your health.

Sleep is a dynamic set of behavioral and psychological state necessary for the support of physical health and general body well-being.

An average human being spends approximately a third of their life sleeping. We are living in a society where everyone is in a rat race. Sleep is not regarded as necessary. The reality is that sleep plays a massive role in how the body functions.

The belief that the body is inactive when we are asleep is a myth. Sleep is an active process. The body and the brain stay active during sleep. The phase of sleep associated with dreams involves rapid eye movements. Other activities observed during sleep include muscle contraction and irregular respiratory and heart rates.

Sleep is a natural process. However, falling asleep is not guaranteed. Some people struggle to fall asleep. Some experience irregular sleeping patterns, while some do not get any sleep at all.


Sleeplessness can be caused by stimulation just before going to sleep, too much caffeine, medication, excitement, jet lag, or anxiety. Sleep disorders like insomnia and irregular patterns can change the way one sleeps.

Sleep is an essential part of our lives. We are going to explore how long one can go without sleep. But first, we need to understand the relationship between sleep and our bodies.

How Sleep Affects Body Functions

The amount of sleep one can get affects how their body works. It affects the brain, the immune system, and the heart.


memory while sleep

It is easier to learn a task when one is well-rested. Getting enough sleep can help one have good moods, maintain high energy levels, increase concentration span, and improve productivity.

The formation of brainwaves during sleep leads to the formation of certain types of memory. Enough sleep helps ease acquisition, consolidation, and recalling of memory.

Immune System

Immune System during sleep

During sleep, the immune system releases a large group of a protein called cytokines. They are meant to promote sleep. These proteins released during sleep also check if the body has infections or inflammations.


cardiovascular health while sleep

The heart rate falls and rises during different phases of sleep. These changes promote cardiovascular health.

How Long We Should Sleep

Sleep refreshes the mind and empowers the body. It can also help reduce stress, maintain blood pressure, and strengthen the immune system.

Sleep has a significant effect on one’s moods and weight maintenance. We cannot underestimate the power of sleep.

Sleep needs may vary from one person to another. It may go with age, activity, health and the food one eats.

Sleep Duration Guidelines

The sleep foundation breaks down how much sleep different age groups need. Children and teens need more sleep as compared to adults. They need sufficient sleep for their mental and physical development.

  • Newborns from the age of 0-3 months old need 14-17 hours of sleep.
  • Infants from the age of 4-11 months old need 12-15 hours of sleep.
  • Toddlers from the age of 1-2 years old need 11-14 hours of sleep.
  • Preschool children from the age of 3-5 years old need 10-13 hours of sleep.
  • School-age kids from the age of 6-13 years old need 9-11 hours of sleep.
  • Teenagers between the ages of 14-17 years need 8-10 hours of sleep.
  • Young Adults from the ages of 18-25 years need 7-9 hours of sleep.
  • Adults between the ages of 26-64 years need 7-9 hours of sleep.
  • Adults between ages 65 or more years old need 7-8 hours of sleep.

Sleep Deprivation Effects

You cannot cheat sleep. Insufficient sleep leads to a buildup known as sleep debt. Sleep debt is the difference between the amount of sleep you should be getting and the sleep you are getting.

According to Katherine Dudley, not even long sleep during weekends can make up for the rest you missed. Making up for a buildup of sleep debt has its effects. It may cause increased calorie intake, increased weight, and reduced energy levels.

The short term effects of sleep are headaches, fatigue, dizziness, and bad moods. In the long term, chronic sleep disorders can be fatal, as shown below.

Immune System

Immune System weaken with lack of sleep

Lack of sleep can weaken the immune system. Research shows that lack of sleep can increase the chances of being sick. These proteins are also released to the body when it has an infection. Lack of proper sleep will lead to low production of cytokines. These cytokines are responsible for mediating immunity and inflammations.

Heart Conditions and Irregularities

Heart Conditions and Irregularities

Studies show how the rise and fall of the heart rate during sleep can help improve cardiovascular health. Lack of sufficient sleep can turn out hazardous to your heart. It has been associated with heart problems like diabetes and high blood pressure.


Obesity with lack of sleep

Obesity develops when energy intake is greater than the energy you use. Sleep affects signals from the brain which control appetite. Lack of sleep can lead to increased food intake

Metabolic Syndrome

sleeplessness affects body metabolism

A science daily article shows research that was carried out to show how sleeplessness affects body metabolism. Sleep deprivation can make one feel less full after a meal. This may lead to excess food intake. Apart from that, it changes how fat is metabolized in the body. Sleep deprivation results in a reduction of glucose tolerance by around 40%.

How Long Can You Go Without Sleep?

A 1964 study of sleep deprivation confirmed that humans could go up to 264 hours without sleep. Actually, it's a very extreme figure. Well, let's take a look at some of the less extreme figures.

Twenty Hours Without Sleep

Twenty Hours Without Sleep

Most people start feeling the effect of lack of sleep within the first twenty-four hours. Sleeplessness for twenty hours has similar effects, like having 0.10 blood alcohol content. It has exceeded the 0.08 limit beyond which it is illegal to drive.

After a whole day without sleep, you will start feeling the effects like drowsiness, impaired judgment, stress, and memory lapse, reduced coordination, and increased sugar levels in the blood.

Forty-Eight Hours Without Sleep

how long go without sleep

The effects of sleeplessness after forty-eight hours intensify. A feeling of fatigue starts to kick in. The feeling of sleep persists. The brain enters into a state of involuntary sleep called microsleep. During the micro sleep state, the mind is unconscious.

The possible effects of sleeplessness for forty-eight hours include anxiety, extreme fatigue, irritability, depersonalization, and inflammation.

Seventy-Two Hours Without Sleep

Seventy-Two Hours Without Sleep

The urge to fall asleep increases. Fatigue increases even further. The sleeplessness starts affecting concentration and memory.

One may start experiencing an overpowering need for sleep, especially in the morning. Remaining awake is only possible if someone tries to keep you awake. At this point, the brain involuntarily enters into a state of sleep.

Staying this long without sleep may cause extreme fatigue, depression, paranoia, hallucination, lack of concentration, and inactivity.

Signs of Sleep Deprivation

Signs of Sleep Deprivation

The signs that you haven’t been getting enough sleep are apparent.


Sleep Deprivation eyes

Red eyes or eye bags are signs you are not getting enough sleep.


Sleep Deprivation Skin

Skin acne is sometimes associated with a lack of sleep.

Weight Gain

Sleeplessness can lead to an increased intake of sugar, which may result in increased weight. It also reduces glucose tolerance by 40 % during metabolism.


Sleep Deprivation Moods

Lack of sleep may lead to stress, anger, and mental exhaustion.


Sleep Deprivation explained

Depression can be caused by fatigue.


Sleeplessness has a significant memory effect.


If you still feel tired in the morning, it is a clear indication you didn’t have enough sleep. This may be accompanied by a sore throat, dry mouth, or a headache.


We have seen it is possible to go for three days without sleep. However, Sleeplessness does more harm than good to the body. Staying for long periods without sleep does affect not only the mind but also the heart. You will not be able to perform your tasks effectively. You cannot even make up for the time you missed sleep.

Sleep is an essential part of our wellness. It should be taken with the same seriousness as fitness and nutrition. The information we have provided will help you make better sleep choices.

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