8 Consequences of Sleep Deprivation: How Long Can You Last Without Sleep?

How long can a person last without sleep?

What is sleep?

Sleep is a necessary biological function that allows our bodies and minds to recuperate and replenish. It is essential for preserving our physical and mental wellness. Yet, certain circumstances, including work obligations or crises, may necessitate a person being awake for extended periods of time. This overview will look at how long a person can go without sleeping and the effects of sleep deprivation. In this article:

  1. What happens when we don’t get enough sleep?
  2. How long can a person last without sleep?
  3. What happens after 24 hours without sleep?
  4. What happens after 36 Hours without sleep?
  5. What happens after 48 Hours without sleep
  6. What happens after 72 Hours without sleep?
  7. How much sleep does a person need according to their age?
  8. The consequences of sleep deprivation
  9. FAQS
  10. Conclusion

What happens when we don’t get enough sleep?

Throughout history, different studies have been carried out on sleep deprivation and it has been observed that, depending on the intensity and frequency, the lack of rest can cause one or more of the following symptoms:

  • Muscle pain
  • Blurry vision
  • color blindness
  • daytime sleepiness
  • Heart problems

Swedish scientists claim that a lack of sleep causes brain damage, after finding a high concentration of the brain’s own molecules in the blood of volunteers who spent a whole night without sleep. Their study shows that a night of sleep deprivation can cause loss of brain tissue, demonstrated by high blood concentrations of two brain molecules after the sleepless night.

During the study, 15 average-weight men experienced one night of sleep deprivation, followed by an eight-hour night of sleep. The researchers found that the levels of these molecules in the blood were higher in the morning after sleep deprivation, compared to the morning after a full night’s rest.


Earlier, other researchers at the University of Surrey found that lack of sleep can also have an impact on genes, with the consequences of a week of not getting enough rest (less than six hours of sleep each night) causing changes in more than 700 genes, although the researchers noted that the function of each gene is not yet fully understood.

How long can a person last without sleep?

The amount of time a person may go without sleep is determined by a variety of factors, including age, health, and individual variances. The average healthy adult may go up to three to four days without sleeping, but in severe circumstances, some people have gone up to 11 days without sleeping. This, however, is uncommon and harmful.

What happens after 24 hours without sleep?

We’ll look at what happens to the human body after 24 hours of sleep deprivation and the long-term effects.

The First Twenty-four Hours Without Sleep

The first 24 hours without sleep may not seem like a huge problem, but it can have a variety of effects on your body and mind. The following are some of the most typical side effects of sleep deprivation during this time:

Fatigue and lethargy: 

When you don’t get enough sleep, your body doesn’t have time to replenish, leaving you tired and sluggish.

Trouble concentrating:

Sleep deprivation can make it difficult to concentrate and remember information.

Changes in mood: 

Sleep deprivation can have an impact on your emotional stability, creating irritation, mood swings, and increased stress.

Decreased response time: 

Sleep deprivation can slow your reflexes and reaction time, reducing your ability to complete daily duties safely.

What happens after 36 hours without sleep?

The first 24 hours of sleep deprivation can cause weariness, lethargy, difficulties concentrating, mood swings, and slower reaction time. Yet, the consequences of sleep deprivation worsen over time.

Without Sleep for the Next 12 Hours

The effects of sleep deprivation worsen after 24 hours. Individuals may begin to experience the following symptoms at this point:


Involuntary brief periods of sleep can lead to dangerous situations, such as driving or operating heavy machinery.

Cognitive impairment:

Sleep deprivation can result in cognitive impairment, such as memory loss, forgetfulness, and difficulty concentrating.


Sleep deprivation can cause hallucinations, in which people see, hear, or feel things that are not present in reality.

Increased irritability:

Increased irritability: Sleep deprivation can contribute to mood swings and problems controlling emotions.

What happens after 48 hours without sleep?

In today’s fast-paced society, sleep deprivation is frequent. Many people forego sleep in order to fulfill work or school deadlines, care for loved ones, or engage in recreational activities. While missing a night’s sleep can have negative implications, staying without sleep for two days or more can have considerably more severe consequences. Including:

Reduced cognitive function: 

Sleep deprivation can have a major impact on cognitive function, including memory, attention, and decision-making capacity.

Physical symptoms:

People may develop physical symptoms such as headaches, muscle aches, and tremors.

Increased risk of accidents:

Accident risk: Sleep deprivation can cause slower reaction times, reduced judgment, and decreased coordination, raising the chance of an accident.

Emotional instability:

Sleep deprivation can cause emotional instability, such as mood swings, anger, and feelings of depression.

What happens after 72 hours without sleep?

Sleep deprivation can be life-threatening after 72 hours without sleep. You may feel extremely tired, confused, and disoriented. Your body may begin to shut down, increasing the likelihood of organ failure.


Microsleeps are tiny periods of sleep lasting only a few seconds. These microsleeps can occur even when the individual is engaged in an activity that demands their full concentration, such as driving, and are potentially harmful. The individual may also have apnea episodes, in which they cease breathing for a few seconds, resulting in snoring or gasping for air.

Cognitive decline:

Cognitive decline can drastically damage one’s capacity to think effectively, concentrate, and make judgments.

How much sleep does a person need according to their age?

The National Sleep Foundation states that the amount of sleep a person needs varies based on their age. Here’s a broad rule of thumb:

14-17 hours per day, including naps, for newborns (0-3 months).

12-15 hours per day, including naps, for infants (4-11 months).

Toddlers (1-2 years): 11-14 hours per day, including naps.

Preschoolers (ages 3 to 5): 10 to 13 hours per day, including naps.

9-11 hours a day for school-aged children (6-13 years).

Teens (aged 14-17): 8-10 hours each day.

7-9 hours per day for young adults (18-25 years).

Adults (aged 26 to 64): 7-9 hours each day.

7-8 hours per day for older persons (65 and up).

It should be noted that these are only guidelines, and some people may require more or less sleep than the average for their age group. It is critical to listen to your body and establish how much sleep you require to feel rested and alert during the day.

The consequences of sleep deprivation:

Some of the implications of sleep loss include:

Impairment of cognitive function: Sleep deprivation can impair your capacity to think effectively, concentrate, and make judgments. It can also affect your memory and slow down your reaction speed.

Emotional instability: Lack of sleep can make you angry, worried, and grumpy. It may also raise your chances of acquiring depression or other mood disorders.

Weakened immune system: Sleep is essential for immune system strength, and prolonged sleep deprivation can make us more susceptible to infections, viruses, and illnesses.

Increased risk of accidents: Drowsiness and weariness caused by sleep deprivation can affect your judgment and reflexes, increasing your risk of accidents and injuries. This is especially hazardous when driving or operating large machinery.

Obesity and weight gain: Sleep deprivation can affect the hormones that control hunger and metabolism, resulting in increased appetite, desires for unhealthy foods, and weight gain.

Increased risk of chronic diseases: Sleep deprivation has been related to an increase in the chance of developing chronic diseases such as diabetes, heart disease, and stroke.

Accelerated aging: Prolonged sleep deprivation can hasten the aging process, causing wrinkles, fine lines, and other indications of age to appear.

Bad performance at work or school: Sleep deprivation can have a negative impact on your productivity, creativity, and general performance at work or school.

Sleep deprivation can have serious ramifications for our physical and mental health, as well as our overall quality of life. As a result, it is critical that we prioritize sleep and receive enough rest each night.


How long can a person go without sleep?

A person can go several days without sleeping, but the actual time depends on the individual’s health, age, and other factors.

What happens to your body when you don’t get enough sleep?

When you don’t get enough sleep, your body becomes exhausted and your cognitive performance suffers. Prolonged sleep deprivation can weaken the immune system, cause weight gain, and increase the risk of chronic diseases.

Is it possible to die from a lack of sleep?

It is possible to die from a lack of sleep, albeit this is uncommon. Extreme sleep deprivation can cause hallucinations, convulsions, and death.

How long can you go without sleeping before experiencing hallucinations?

After 24-48 hours of sleep deprivation, some people may begin to experience hallucinations. This, however, differs depending on the individual.

Is it possible to function in the absence of sleep?

While it is possible to live without sleep for brief periods of time, persistent sleep deprivation can have serious effects on our physical and mental health.

How does a lack of sleep influence the brain?

Sleep deprivation can have a negative impact on cognitive function, memory, and focus. It can also raise the likelihood of acquiring mood disorders including anxiety and sadness.

How can you tell if someone is tired?

Fatigue, irritability, difficulty concentrating, and mood changes are common symptoms of sleep deprivation.

How can a lack of sleep affect physical health?

Sleep deprivation may wreak havoc on the immune system, increase the risk of chronic diseases like diabetes and heart disease, and contribute to weight gain and obesity.

How can you recover from a lack of sleep?

Getting adequate restorative sleep is the greatest approach to recovering from sleep loss. It’s also critical to practice excellent sleep hygiene habits, such as avoiding caffeine and alcohol before night and sticking to a consistent sleep schedule.

How long does it take to recover from a lack of sleep?

The amount of time it takes to recover from sleep deprivation varies according to the individual’s health and the severity of their sleep loss. Most people, however, may recover within a few days to a week of good-quality sleep.


To summarise, while it is possible to stay awake for an extended period of time, it is critical to prioritize getting enough restorative sleep. Prolonged sleep deprivation has serious effects on our physical and mental health, increasing our risk of chronic diseases, impairing cognitive function, and causing mood disorders. We can ensure that we get the rest we need to live happy, healthy lives by developing good sleep hygiene habits and obtaining medical care when necessary. Recall that sleep is a necessity, not a luxury, and that it should be prioritized in our everyday life.

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