Sleep Deprivation: The Impact Of 5 Days Without Sleep

Sleep is essential for our physical, cognitive, and mental well-being. While the amount of sleep required varies from person to person, going without sleep for an extended period can have detrimental effects on the body and mind. So, what happens if you don't sleep for five days? After just 24 hours without sleep, individuals may experience impaired coordination, memory, and judgment, similar to the cognitive impairment caused by alcohol intoxication. As time progresses, the symptoms of sleep deprivation become more severe, with increased mood changes, physical health issues, and cognitive impairments emerging. By 48 hours, extreme sleep deprivation sets in, with the body resorting to microsleeps—brief periods of rest where the brain temporarily shuts down. At the 72-hour mark, individuals may experience severe cognitive deficits, hallucinations, and a fragile emotional state. Going without sleep for five days (120 hours) likely results in an even more profound disruption of mental and physical functioning, though there is limited research on the specific effects at this duration.

After 24 hours, you may experience impaired coordination, memory, and judgement

After 24 hours without sleep, you will likely experience cognitive difficulties, including impaired coordination, memory, and judgement. This is 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. As a result, you may experience concentration and memory difficulties, reduced coordination, short-term memory problems, and a higher risk of accidents.

In fact, the effects of going without sleep for 24 hours are comparable to having a blood alcohol content (BAC) of 0.10%, which is over the legal driving limit in the US of 0.08%. You may also experience increased levels of stress hormones, such as cortisol and adrenaline, as your body attempts to compensate for the fatigue. This can lead to an increased risk of fatal accidents, as your reaction time decreases and you experience slurred speech and slowed thinking.

Research has also shown that lack of sleep for 24 hours can make individuals more emotionally reactive, with decreased attention and impaired hearing. A small study published in the Journal of Sleep Research in 2016 found that a lack of sleep made participants more likely to recall false memories. Overall, after 24 hours of sleep deprivation, individuals can expect to experience a range of cognitive and physical impairments that can impact their daily functioning and increase their risk of accidents.

After 36 hours, you may experience increased mood changes, alterations in brain function, and physical symptoms

After 36 hours of sleep deprivation, you will likely experience a wide range of physical and mental health issues.

The stress hormone cortisol will continue to increase, and your body will be under considerable stress. You may experience mood swings, with crankiness and edginess worsening. You will also likely feel sluggish, with delayed reaction times, foggy memory, and an inability to concentrate, learn new information, or process social cues.

Your sleep-wake cycle, which helps regulate the release of hormones such as cortisol, insulin, and human growth hormone, will be disrupted. This will alter several bodily functions, including your body temperature and appetite. You may also experience inflexible reasoning and speech impairments, such as poor word choice and intonation.

Additionally, you may start to hallucinate, with simple visual hallucinations such as seeing something growing from the floor.

After 48 hours, you may experience microsleeps and disorientation

After 48 hours of sleep deprivation, you enter a state of extreme sleep deprivation. Your body will start to shut down for microsleeps—brief periods of rest lasting 3 to 15 seconds. During these microsleeps, your brain switches off, and you may experience a lapse in attention. Your eyes may close, or they may remain open, giving the appearance that you are still awake. However, during microsleep, your brain is not processing external information as it usually does.

Microsleeps can be dangerous, especially if you are driving or operating heavy machinery. Even a few seconds of microsleep can be enough to cause a serious accident. The National Highway Traffic Safety Administration estimates that up to 6,000 fatal crashes each year may be linked to drowsy drivers.

In addition to microsleeps, after 48 hours without sleep, you may experience disorientation and perceptual distortions. Your memory will be foggy, and your thinking impaired. You are also likely to feel increased irritability and anxiety. Some people may even start to hallucinate or experience mood swings, with some feeling depressed and others euphoric.

The longer you go without sleep, the more severe and intolerable the symptoms become. By 72 hours, you will experience major cognitive deficits, and your hallucinations may become more complex. Microsleeps will also increase in length and frequency as your body desperately tries to compensate for the lack of sleep.

After 72 hours, you may experience major cognitive deficits and hallucinations

After 72 hours without sleep, you will likely experience severe cognitive deficits and hallucinations. Your ability to regulate your emotions and accurately perceive the world around you will be severely compromised. You will be irritable, anxious, and depressed, and you will struggle with executive functioning and thinking. Your mind will be ripe for hallucinations, delusions, and paranoia. You may also start to have illusions, struggling to interpret something that is there, such as reading other people's emotions or knowing whether what you're seeing is human.

Microsleeps, which are 3- to 15-second bursts of rest during which your brain switches off, will increase in length and frequency. While microsleep may feel like a protective response by the body, these moments of involuntary rest are incredibly risky if you are driving, operating heavy machinery, or making important decisions.

Research has shown that staying awake for 72 hours can cause symptoms similar to acute psychosis or a loss of touch with reality. A 2015 study found that two astronauts who stayed awake for 72 hours experienced impaired cognitive functioning, increased heart rate, and a reduction in positive emotions.

The effects of sleep deprivation will intensify the longer a person stays awake. After 72 hours, a person will have profound difficulty with mood and cognition, and their fatigue will be extreme.

After 96 hours, your perception of reality may be severely distorted, resembling acute psychosis

Sleep is essential for our physical, cognitive, and mental well-being. Staying awake for an extended period can have severe consequences on our health. While the amount of time a person can survive without sleep is unclear, the current world record for the longest time without sleep is 266 hours, or just over 11 days, set by Randy Gardner in 1963.

After 96 hours (or four days) without sleep, an individual's perception of reality may become severely distorted, resembling acute psychosis. This means that their ability to accurately perceive the world around them is severely compromised. They may experience complex visual hallucinations, such as seeing fully formed images, and auditory hallucinations, such as hearing a dog bark when there is none. They may also experience delusions or false beliefs, such as believing that someone has sent them on a secret mission. These symptoms are similar to those of acute psychosis, indicating a loss of touch with reality.

In addition to these perceptual distortions, an individual who has been awake for 96 hours will likely experience other physical and mental health symptoms. Their urge to sleep will be incredibly strong, and they may experience microsleep, which is when the brain briefly goes offline for a few seconds without the person realizing it. They may also exhibit extreme sleep deprivation symptoms such as irritability, anxiety, foggy memory, and impaired thinking.

The effects of sleep deprivation can be dangerous, and it is important to prioritize getting adequate sleep to maintain overall health and well-being.

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