Can You Survive Without Sleep? How Long Can We Stay Awake?

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I know I’ve asked myself this question about a million times:

How long will you can survive without sleep?

Keep reading, and I’ll let you know what I have found on the topic.

The “No Sleep” Timeline

At 24 Hours

f you’ve pulled an all-nighter studying for an exam or preparing for a presentation at work, you’re going to wish you didn’t procrastinate.

When you’ve gone 24 hours without even a nap, you’re not going to be able to think as clearly. In fact, your brain will work the same as someone with a blood alcohol content of .10, which is above the legal limit to be convicted of a DUI in all 50 US states.

Get More Info: One Hour of Sleep – Is It Enough?

In addition to cognitive impairment, you’ll experience the following:

  • Lack of good judgment
  • Impaired memory
  • Poor decision-making
  • Decrease in hand-eye coordination
  • Lower attention span
  • Emotional tendencies
  • Impaired hearing
  • Increase risk of death from a fatal accident

Want to know more? See the latest findings on how one night of poor sleep affects our health.

At 36 Hours

A consecutive stint of 36 waking hours will start to negatively affect your physical health. Repeated exposure to this bad habit can lead to cardiovascular disease, high blood pressure, and hormone imbalances. You may experience complete memory lapses and not remember what happened during these hours.

At 48 Hours

Two straight days of deprivation results in something called “microsleeps.” Even though the name sounds kind of cute, microsleeps are anything but. These are miniature blackouts that can last anywhere from half of a second to about 30 seconds. You won’t be aware that it’s even happening, but when you come to, you’ll be disoriented.

At 72 Hours

If you go three days straight without dozing, you’re liable to start experiencing hallucinations. In fact, your brain is struggling to keep it together. Concentrating, staying motivated, and even having a simple conversation will seem like strenuous mental tasks.

Sleep Deprivation – Possible Causes & Symptoms

Morvan’s Syndrome

In some cases, sleep deprivation isn’t a choice. No matter how much we want or need to rest, our bodies simply aren’t having it.

A classic example of this is something called Morvan’s syndrome. Subjects with this medical disorder were studied, and it was found out that people with this disorder sleep very little. One particular case involved a man in France who went several months with barely a wink. Instead, he had periods of hallucination and pain in his extremities.

Besides pain and sleeplessness, other symptoms of Morvan’s syndrome include muscle twitching, sweating, and weight loss.

Fatal Familial Insomnia

People with fatal familial insomnia (FFI) can expect to die within six to 30 months. The extreme deprivation associated with FFI results in organ failure and degeneration of parts of the brain.

It is considered an infectious disease (in the same family as mad cow disease), but you can’t get it from casual touching or sexual intercourse with someone who’s infected. In order to catch FFI, you’d have to be in contact with the actual brain of someone with the disease or receive a blood transfusion from tainted blood.

Sleep Apnea

Up to 22 million Americans may be suffering from sleep apnea. This disorder occurs when your airway becomes blocked, reducing or eliminating airflow. People with this condition can wake up several times per night, causing severe sleep deprivation if left untreated.

Common causes include obesity, large tonsils, endocrine disorders, heart or kidney failure, genetic disorders, and premature birth. If you have this, it can also negatively affect the quality of rest that your partner gets.

Restless Legs Syndrome

Restless legs syndrome (RLS) is a nervous system disorder that creates an uncontrollable urge to reposition your legs. It’s accompanied by uncomfortable tingling and twitching, commonly described as “pins and needles” or a “creepy crawly” feeling.

While this disorder is most common among middle-aged women, anyone can suffer from these symptoms, and it’s estimated that it affects up to 10% of the population.

Night Terrors

Children experience night terrors. Unlike nightmares, night terrors are more like a hallucination that lasts anywhere from a few minutes up to 30 minutes. The child is awake during the ordeal, though they often won’t remember what they saw.

How Long Can You Go Without Sleep?

There’s no definitive answer to how long you can stay awake. There’s even debate about whether we need all phases of sleep to survive. For example, while most scientists agree that the REM cycle is necessary for survival, there are cases of people who have sustained brain injuries that deprive them of this cycle. They’ve been able to survive, and even thrive, after these injuries, so the jury is still out.

There is an anecdotal story of a young man in China who forced himself to stay awake and died after 11 days, but there were other factors involved. The ethical dilemma involved in testing these boundaries is too great to define a specific timeline.

Frequently Asked Questions

Can you die from lack of sleep?

While not sleeping won’t outright kill you, the effects it has on your body can be fatal. After several days of not sleeping, your organs begin to shut down, and sections of your brain will degenerate.

Also, lack of rest inhibits your judgment and alertness, so you’re more likely to make a fatally bad decision or be involved in an accident.

How long will it take before you start hallucinating?

While every person is different, on average, you can expect to start hallucinating after 72 hours of deprivation.


It may be tempting to try to trick your body into staying awake. Think about how much more you could accomplish if you slept less, or not at all? Based on the research, it’s not advisable to deprive yourself of shut-eye, especially for long periods of time.

If you find that you need more time in the day and you genuinely want to cut out the amount of time you’re in bed, you may want to try something like polyphasic sleep, where you nap for short bursts during a 24-hour period. This method has been found to increase productivity and the number of waking hours in the day, although its safety as a long-term habit is also debatable.

Jill Zwarensteyn

Jill Zwarensteyn


About Author

Jill Zwarensteyn is the Editor for Sleep Advisor and a Certified Sleep Science Coach. She is enthusiastic about providing helpful and engaging information on all things sleep and wellness.

Combination Sleeper

Sleep Advisor