The Centers for Disease Control and Prevention (CDC) recommend that adults between the ages of 18 and 60 years get at least 7 hours of sleep a night. However, approximately 35 percent of adults in the United States do not get enough sleep.
Adults should stay awake no longer than 17 hours to meet the CDC’s sleep recommendation. People tend to experience the adverse effects of sleep deprivation within 24 hours.
In this article, we explore how long a person can go without sleep and look at the effects of sleep deprivation over 72 hours.
We also discuss the short- and long-term health effects of sleep deprivation, how much sleep a person needs, and how to improve sleep hygiene.
How long can a person go without sleep?
Most adults require at least 7 hours of sleep a night.
Sleep requirements vary between people and also depend on a person’s age. For example, infants require about twice as much sleep as adults.
However, the amount of time that a person can survive without sleep remains unclear. According to a 2010 review, the current world record for a person going without sleep is 266 hours, which equates to just over 11 days.
The most famous sleep deprivation experiment took place in 1964 when a Californian high school student named Randy Gardner managed to stay awake for 264 hours.
Toward the end of the 11 days, Gardner grew paranoid and even started hallucinating. However, he reportedly recovered without any long-term physical or psychological effects.
What is sleep deprivation?
Sleep deprivation occurs when a person gets less sleep than their body needs. The effects of sleep deprivation can vary from person to person.
Children and teenagers need more sleep than adults as their brains and bodies are still developing and growing. As such, the effects of sleep deprivation in children can sometimes be more severe or longer-lasting.
General symptoms of sleep deprivation in adults can include:
- fatigue and sleepiness during the day
- concentration, alertness, and memory difficulties
- reduced coordination
- irritability
- increased appetite
- mood changes
Regular or chronic sleep deprivation can also increase a person’s risk of several health conditions, including obesity, diabetes, and heart disease.
Can sleep deprivation kill?
Sleep deprivation can be fatal in certain circumstances.
For example, sleep deprivation can increase the risk of dangerous accidents. According to the National Highway Traffic Safety Administration (NHTSA), in 2015, U.S. police reported 90,000 motor vehicle crashes that involved sleep-deprived drivers. The NHTSA also state that drowsy driving claimed 795 lives in 2017.
An incredibly rare sleep disorder called fatal familial insomnia (FFI) can also result in death.
FFI is an inherited condition that results from a mutation in the prion protein (PRNP) gene. The mutated gene produces misfolded prions that accumulate in the thalamus, which is the region of the brain that regulates sleep.
The symptoms of FFI typically present in middle adulthood and include:
- mild insomnia that gets progressively worse
- weight loss
- lack of appetite
- changes in body temperature
- dementia that progresses rapidly
There is currently no cure for FFI, and death usually occurs within 12–18 months of a person first experiencing symptoms.
24 hours without sleep
A person may experience impaired coordination and memory after 24 hours without sleep.
Most people will begin to experience the effects of sleep deprivation after just 24 hours. The CDC claim that staying awake for at least 24 hours is comparable to having a blood alcohol content (BAC) of 0.10 percent. In the U.S., it is illegal to drive with a BAC of 0.08 percent or above.
The effects of going without sleep for 24 hours can include:
- drowsiness
- irritability
- concentration and memory difficulties
- reduced coordination
- impaired judgment
- short-term memory problems
- raised levels of stress hormones, such as cortisol and adrenaline
- increased blood sugar levels
- a higher risk of accidents
- muscle tension
Many of these effects occur because the brain attempts to conserve energy by entering a state that doctors refer to as “local sleep.” During local sleep, the body temporarily shuts down neurons in some regions of the brain but not others.
People who have entered local sleep may appear fully awake, but their ability to perform complex tasks will significantly decline.
Sleep deprivation also disrupts the body’s natural sleep-wake cycle, which affects hormones that regulate:
- growth
- appetite
- metabolism
- stress
- the immune system
48 hours without sleep
The effects of sleep deprivation intensify the longer a person stays awake. After going without sleep for 48 hours, a person’s cognitive performance will worsen, and they will become very fatigued.
At this point, the brain will start entering brief periods of complete unconsciousness, also known as microsleep. Microsleep occurs involuntarily and can last for several seconds.
72 hours without sleep
After 72 hours without sleep, deprivation symptoms and fatigue will intensify even further. Going for 3 days without sleep will have profound effects on a person’s mood and cognition.
In a 2015 study, two astronauts experienced impaired cognitive functioning, increased heart rate, and a reduction in positive emotions after staying awake for 72 hours.
Some effects of staying awake for 72 hours include:
- extreme fatigue
- difficulty multitasking
- severe concentration and memory issues
- paranoia
- depressed mood
- difficulty communicating with others
Short-term effects of sleep deprivation
Sleep deprivation can have several adverse effects on health that will resolve once a person gets enough sleep.
Short-term effects of sleep deprivation can include:
- drowsiness
- reduced alertness
- decreased concentration
- impaired judgment
- short-term memory problems
- stress
- a higher risk of accidents
Long-term effects of sleep deprivation
Extreme sleep deprivation can cause anxiety and depression.
Chronic sleep deprivation can have lasting effects on a person’s health. These can include an increased risk of:
Chronic sleep deprivation can also have significant long-term effects in children, including:
- poor academic performance
- problems getting along with others
- a higher risk of engaging in dangerous and antisocial behaviors
- problems with physical growth and development
How much sleep does a person need?
Sleep requirements vary between people and depending on a person’s age.
The CDC provide the following recommendations for how much sleep people need on average:
| Age group | Recommended amount of sleep per day (hours) |
| 0–3 months | 14–17 |
| 4–12 months | 12–16 (including naps) |
| 1–2 years | 11–14 (including naps) |
| 3–5 years | 10–13 (including naps) |
| 6–12 years | 9–12 |
| 13–18 years | 8–10 |
| 18–60 years | 7 or more |
| 61–64 years | 7–9 |
| 65 years and older | 7–8 |
General sleep hygiene tips
Quality matters as much as quantity when it comes to sleep. Practicing good sleep hygiene can promote higher quality sleep. People can improve their sleep hygiene by taking certain actions that can lead to improved sleep quality and daytime alertness.
Sleep hygiene tips include:
- maintaining a consistent sleep schedule by going to sleep and waking up at the same time each day, including at weekends
- removing electronic devices, such as smartphones, computers, and televisions, from the bedroom
- keeping the bedroom dark and at a comfortable temperature
- avoiding stimulants, such as caffeine and nicotine, before bedtime
- winding down before going to bed, for example, by having a warm bath, reading a book, or doing relaxation exercises
- exercising regularly but avoiding vigorous physical activity just before going to bed
- avoiding eating close to bedtime
- limiting daytime naps to less than 20 minutes
Summary
Sleep deprivation occurs when a person does not get enough sleep. It is not clear how long a person can go without sleep, but in a famous experiment, a person managed to stay awake for 264 hours.
According to the CDC, at least one in three U.S. adults are not getting enough sleep. Missing 1 or 2 hours of sleep may not seem like a big deal, but it can negatively affect a person’s mood, energy levels, and ability to handle complex tasks.
Chronic sleep deprivation can increase a person’s risk of cardiovascular diseases, obesity, and diabetes.
Most adults need around 7 hours of sleep each night. Practicing good sleep hygiene can promote a better quality of sleep. Sleep hygiene tips include keeping to a consistent sleep schedule, winding down before bedtime, and avoiding caffeine in the evening.