How Long Can You Go Without Sleep Before It Becomes Dangerous?

A sleepless woman sitting up in bed.

Are you worried about how going without sleep for 24 hours straight will affect you? Many people have been in this sleepless situation, whether you're a new parent or cramming for a big exam.


While going 24 hours without sleep won't have lasting effects on your health, it will still take a toll on your mind and body. However, extreme sleep deprivation will significantly harm your well-being and health.


This article discusses the effects of sleep deprivation. It’ll also cover how much sleep you need to stay healthy and tips on how to fall asleep.

Key Takeaways

  • There’s no new or clear evidence on how long you can go without shuteye, as experts consider conducting relevant experiments unethical due to the inherent safety risks.

  • Sleep deprivation can indirectly cause death through accidents. It also increases the risk of conditions like diabetes, heart and kidney disease.

  • Sleep deprivation causes a progressive worsening of mental and physical functions, including fatigue and mood swings, hallucinations, microsleeps, weakened immunity, and a decline in mental health.

  • Chronic sleep deprivation leads to sleep debt, which results in short-term problems like cognitive issues and stress, and an increased risk of developing life-threatening diseases like colorectal cancer.

Table of Contents

How Long Can You Go Without Sleep?

A man sitting on a couch. There is a calendar on the wall marking the number of days he has gone without sleep.

There isn’t any solid evidence on how long you can go without sleep. While older research has studied the topic, there are no recent findings. However, many studies highlight that sleep deprivation negatively impacts health and overall well-being.


In 1963, 17-year-old Randy Gardner lasted 11 days and 24 minutes without sleep before throwing in the towel. Others broke his record several times, ending with Robert McDonald for the Guinness World Records with 18 days and 21 hours.


Experts have deemed it “unethical” to test the boundaries of going without sleep, and rightly so. Missing out on just 24 hours of sleep has effects that go beyond daytime sleepiness, such as fatigue and difficulty concentrating.


The longer you go without sleep, the riskier and more severe the negative short- and long-term effects. An example of a short-term effect would be headaches. A long-term effect would be short-term memory loss. Since sleep affects your lifespan, not getting enough of it will ultimately decrease your longevity.

Can You Die From a Lack of Sleep?

The short of it is: yes, you can die from lack of sleep. However, the cause of death is more likely to be an accident due to sleep deprivation.


Let’s look at vehicular accidents in particular. A study published in Oxford Academic found that getting less than 7 hours of sleep in 24 hours increases the risk of causing a car accident. Those who slept 4 hours were, on the other hand, more likely to be victims of single-car crashes.(1)


Severe sleep deprivation can also cause death by increasing your risk of health conditions like diabetes and heart disease.


However, there is a disease called Fatal Familial Insomnia (FFI), which eventually leads to death. FFI is hereditary and has symptoms that include mobility problems, cognitive decline, high blood pressure, rapid heartbeat, and the inability to sleep at all.


VeryWell Health says FFI has a mean duration of 18 months with no known treatment for disease reversal.(2) It’s important to note that FFI is extremely rare and doesn’t result from sleep deprivation. In most cases of extended sleep deprivation, your body will ultimately force itself to sleep.


If you are regularly sleep-deprived, improving sleep hygiene habits and making lifestyle changes is essential. If these don’t work, consult a healthcare provider to determine the root cause of your sleeplessness and how to address it.

What Happens if You Go 24 Hours Without Sleep?

Here’s what to expect when you go 24 hours without sleep:


  • You will experience impaired physical performance, like fatigue, delayed reaction times and poor coordination. It's equivalent to having a blood alcohol content of 0.10%, which is over the legal limit in most U.S. states.

  • You will experience heightened levels of irritability, stress, depression and anxiety.

  • Your ability to make decisions and mental clarity will decrease.

  • You will have memory lapses or difficulty focusing.

What Happens if You Go 36 Hours Without Sleep?

Going 36 hours without sleep worsens the effects of staying awake for a day.


  • Extreme fatigue sets in, coupled with dizziness. Your reaction times are even slower, and your hand-eye coordination is poorer.

  • Your mood changes are more intense, with a decreased ability to regulate your emotions. You may feel angry, aggressive or euphoric.

  • Your decision-making and information processing abilities, memory and concentration deteriorate.

  • You might experience hallucinations.

  • Bodily functions are negatively affected, including hormonal balance, appetite, metabolism and body temperature.

What Happens if You Go 48 Hours Without Sleep?

Think about it. Going 48 hours without sleep is 2 whole days. There's a gradual progression of adverse effects the longer you stay awake.


There's an increased likelihood of microsleeps at 48 hours without shuteye. These are involuntary, brief periods of sleep that last up to 30 seconds, according to the Cleveland Clinic.(3)


Research published in the National Library of Medicine highlights that staying up for an extended period makes you susceptible to illness. A study conducted on shift workers found that losing sleep results in an increased risk of viral infections due to a weakened immune system.(4)

What Happens if You Don’t Sleep for 72 Hours?

Going without sleep for 3 days is tough because the urge to sleep becomes overwhelming.


Your perception of reality is distorted at this point. Besides frequent hallucinations, you can't accurately perceive what’s there from what isn’t. Your speech is slurred, and you're unable to walk correctly.


According to the Sleep Foundation, going past 120 hours without sleep can have severe consequences on mental health. Psychosis may set in, causing violent behavior.(5)

What Happens When Chronic Sleep Deprivation Becomes an Issue?

A woman with depression due to chronic sleep deprivation.

Staying awake for a day won’t have long-lasting effects if you get recovery sleep. However, acute sleep deprivation is a concern because it poses serious risks to your health and well-being.


Chronic sleep deprivation is when an individual fails to get enough sleep over an extended period. This results in sleep debt, which is accumulated lost sleep that translates to harmful short- and long-term effects.


Research published in the National Library of Medicine highlights examples of short-term consequences of sleep disruption, which include problems with thinking and memory, stress, pain, depression and anxiety. Long-term consequences include diabetes, high blood pressure, heart disease and weight gain. It also increases the risk of cancer and exacerbates digestive issues.(6)

It Causes Cognitive Impairment and Emotional Instability.

We mentioned that sleep deprivation is linked to diminished decision-making, memory and concentration. It’s also associated with mood imbalances and unstable emotions.


A study published in Oxford Academic found that sleep loss increased negative feelings and decreased positive emotions, negatively impacting emotional responses to both.(7)

It Negatively Impacts Mental Health.

Sleep deprivation can worsen anxiety, stress and depression. Poor sleep quality upsets the balance of dopamine and serotonin in the brain. These chemicals are responsible for managing your mood and emotions.


Lack of sleep makes it difficult to handle emotions and stress, leading to stronger emotional reactions. It’s essential to prioritize good sleep to keep your mental health in balance.

It Increases the Risk of Developing Cardiovascular Disease.

There’s a strong link between chronic sleep deprivation and heart disease. Insufficient sleep leads to changes in blood pressure, inflammation and heart rate, contributing to heart issues.


Sleep deprivation also messes with the natural circadian rhythm. According to a study published in the National Library of Medicine, disruptions to the sleep-wake cycle affect cells that line your blood vessels.(8)


This increases the likelihood of blood clots that prevent your blood vessels from relaxing, impeding smooth blood flow, which causes cardiovascular problems over time.

It Disrupts Metabolism, Gut Microbiome and Leads to Weight Gain.

Chronic sleep deprivation can cause hormone imbalance, affecting leptin, ghrelin and adiponectin, the hormones responsible for regulating your appetite. This imbalance makes you crave high-calorie foods, causing you to gain weight and disrupting your metabolism.


Inadequate sleep also affects glucose metabolism and how your body uses insulin, increasing your risk of chronic diseases like obesity and diabetes.


Getting enough restful sleep is essential for a healthy gut. Sleep deprivation upsets the balance of various microorganisms in your gut that help digestion. This imbalance is known as dysbiosis, which leads to metabolic issues, inflammation and compromised immunity.

How Much Sleep Do You Actually Need?

Generally, experts recommend 7 to 9 hours of sleep per night for most adults. However, sleep requirements vary across individuals because sleep changes with age.


Here’s what the National Sleep Foundation recommends per age group(9):


  • Newborns (0 to 3 months): Between 14 and 17 hours, daytime naps included

  • Older infants (4 to 11 months): Between 12 and 15 hours a day

  • Toddlers (1 to 2 years): Between 11 and 14 hours nightly

  • Pre-schoolers (3 to 5 years): Between 10 and 13 hours per night

  • School-age kids (6 to 13 years): 11 hours every night

  • Teenagers (14 to 17 years): 10 hours per night

  • Adults (18 to 64 years): 7 to 9 hours a night

  • Older adults (65 and up): 7 to 8 hours a night

How to Fall Asleep

By now, you understand how important it is to get enough sleep. If you struggle with drifting off or staying asleep, evaluating your lifestyle and practicing good sleep hygiene is essential.


Here are tips to help you fall asleep fast:


  • Stick to a consistent sleep schedule. Go to bed and wake up at the same time every day, even on the weekend.

  • Optimize your bedroom for sleep. Set the thermostat to the best temperature for sleep and keep your environment dark with an excellent sleep mask. Keep things quiet with well-fitting earplugs or mask disruptive sounds with a white noise machine.

  • Craft a relaxing bedtime routine that might include soaking in a warm bath, reading a book, and meditating.

  • Put your gadgets away at least an hour before bedtime. The blue light emitted by screens signals your brain that it’s time to be up and alert.

  • Maintain a healthy diet and don't eat right before sleeping. If you must snack, be aware of what foods to eat or not to eat before bedtime.

  • Exercise regularly but not too close to bedtime, or you might have trouble falling asleep.


Again, if sleep deprivation persists, a healthcare provider can detect underlying health problems or sleep disorders and prescribe treatment.

Conclusion

It's unclear how long you can go without sleep. What’s clear is that the effects of sleep deprivation can wreak havoc on your health and well-being. The longer you go without sleep, the more severe its effects.


If you're regularly sleep-deprived, it’s essential to make lifestyle adjustments to correct the problem. If nothing seems to work, see a healthcare provider. Extreme sleep deprivation can lead to a myriad of harmful short- and long-term effects, impacting your quality of life.


Did this article help you understand the consequences of sleep deprivation? Let us know by leaving a comment below.

Sources:  

(1) “Acute sleep deprivation and culpable motor vehicle crash involvement.” Oxford Academic, academic.oup.com/sleep/article-abstract/41/10/zsy144/5067408. Accessed 5 May 2025.

(2) “Overview of Fatal Familial Insomnia.” VeryWell Health, www.verywellhealth.com/fatal-familial-insomnia-overview-4588665. Accessed 5 May 2025.

(3) “How Long Can You Go Without Sleep?” Cleveland Clinic, health.clevelandclinic.org/how-long-can-you-go-without-sleep. Accessed 5 May 2025.

(4) “Sleep, immunity and shift workers: A review.” National Library of Medicine, pmc.ncbi.nlm.nih.gov/articles/PMC5241621/. Accessed 5 May 2025.

(5) “How Long Can You Go Without Sleep?” Sleep Foundation, www.sleepfoundation.org/how-sleep-works/how-long-without-sleep. Accessed 5 May 2025.

(6) “Short- and long-term health consequences of sleep disruption.” National Library of Medicine, pmc.ncbi.nlm.nih.gov/articles/PMC5449130/. Accessed 7 May 2025.

(7) “The effect of sleep deprivation and restriction on mood, emotion, and emotion regulation: three meta-analyses in one.” Oxford Academic, academic.oup.com/sleep/article/44/6/zsaa289/6053003. Accessed 6 May 2025.

(8) “Sleep deprivation and endothelial function: reconciling seminal evidence with recent perspectives.” National Library of Medicine. pubmed.ncbi.nlm.nih.gov/33064569/. Accessed 6 May 2025.

(9) “How Much Sleep Do You Really Need?” National Sleep Foundation, www.thensf.org/how-many-hours-of-sleep-do-you-really-need/. Accessed 7 May 2025.


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