For those of us either curious about sleep in general or struggling to get consistent sleep, certain questions can come up. One of those questions may include, how long can we survive without sleep?
Here, we’ll break down the timeline of mental and physical repercussions you can expect without any sleep. We’ll also delve into common reasons why people may struggle to get sufficient sleep.
With that in mind, if you are having sleep issues, it’s wise to consult with your healthcare provider or a sleep specialist in order to find out what’s behind your sleep problems and receive proper treatment.
The “No Sleep” Timeline
At 24 Hours
If 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
- Increased 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.
Have You Gone Without Sleep?
Sleep Deprivation – Possible Causes & Symptoms
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 syndrome1. Subjects with this medical disorder were studied, and it was found that people with this disorder sleep very little. One particular case involved a man in France2 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.1
Fatal Familial Insomnia
Fatal familial insomnia (FFI)3 is a fatal form of insomnia that unfortunately does not yet have a cure. The extreme deprivation associated with FFI results in organ failure and degeneration of parts of the brain. FFI is extremely rare, with fewer than 1,000 Americans having the condition. The cause of FFI is genetic and typically the result of a variant in the PRNP gene. Symptoms may begin presenting in adulthood.3
Obstructive Sleep Apnea
This sleep disorder occurs when your airway becomes obstructed, creating periodic episodes of reduced or zero airflow4.
People with this condition can wake up multiple times per night due to low oxygen levels, causing severe sleep deprivation if left untreated. There are many potential causes of OSA but some common ones may include obesity, physical makeup, sleeping on the back, advanced age, consuming alcohol, or pregnancy.4
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 legs5. It’s accompanied by uncomfortable tingling and twitching, commonly described as “pins and needles” or a “creepy crawly” feeling.
While this disorder is more common among women, anyone can experience these symptoms, and it’s estimated that it affects up to 10 percent of the population. Additionally, people who are middle-aged or older may present more severe symptoms.5
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 story6 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, though, it’s not advisable to deprive yourself of shut-eye, especially for long periods of time.
Instead, we advise focusing on getting a healthy amount of sleep each night in order to have the energy to accomplish all your tasks in a more timely manner.
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.
- Maskery, Mark., et al. “Morvan Syndrome”. The Neurohospitalist. 2016.
- “How Long Can Humans Stay Awake?”. Scientific American. 2002.
- “Fatal familial insomnia”. National Center for Advancing Translational Diseases. Last modified February 2024.
- Slowik, Jennifer M., Sankari, Abdulghani., Collen, Jacob F. “Obstructive Sleep Apnea”. StatPearls. Last modified December 11, 2022.
- “Restless Legs Syndrome”. National Institute of Neurological Disorders and Stroke. Last modified November 28, 2023.
- Dockterman, Eliana. “Euro 2012 Superfan Dies from Sleep Deprivation”. Time Magazine. 2012.