Sleep Deprivation: How Many Days Can You Endure?

Sleep is a vital part of our daily routine, and getting the proper amount of good-quality sleep is crucial for our physical, mental, and emotional health. While it may be tempting to sacrifice sleep in favour of work or other activities, the effects of sleep deprivation can be severe and long-lasting. Even after just 24 hours without sleep, you may experience symptoms such as fatigue, irritability, drowsiness, and cognitive impairment. The longer you go without sleep, the more severe the side effects become, with hallucinations and delusions occurring after 48 hours, and a severe decline in mental health after 120 hours.

After 24 hours: the effects of sleep deprivation

After 24 hours of sleep deprivation, you may experience a range of symptoms, including:

• Fatigue and sleepiness during the day
• Concentration, alertness, and memory difficulties
• Reduced coordination
• Impaired decision-making
• Vision and hearing impairments
• Decreased hand-eye coordination
• Increased muscle tension
• Increased risk of accidents or near misses
• Problems with cognition and thinking, such as short-term memory loss and brain fog
• Lower performance at work or school
• Increased problems with social cues
• Behavioural issues, especially in children
• Changes in visual perception, such as objects appearing different from how they are
• Increased levels of stress hormones, such as cortisol and adrenaline
• Increased blood sugar levels

These effects are similar to those of alcohol intoxication, with the Centers for Disease Control and Prevention (CDC) claiming that 24 hours of sleep deprivation is comparable to having a blood alcohol content (BAC) of 0.10%, which is above the legal driving limit in the US of 0.08%.

While missing 24 hours of sleep won't cause major health problems, it can increase your risk of errors and accidents in everyday tasks.

After 36 hours: increased appetite and extreme fatigue

After 36 hours of sleep deprivation, you will likely experience increased appetite and extreme fatigue. This is where the physical impact of sleep deprivation becomes more prominent.

At this stage, your body starts to experience hormone imbalances, with higher levels of inflammatory markers in the blood. This will cause fluctuations in your body temperature and appetite. You may also start to have microsleeps, which are brief moments of involuntary sleep or drowsiness. These can last up to 30 seconds, and you may not even realise they are happening. Microsleep can be dangerous, especially if you are driving or operating heavy machinery.

The side effects of sleep deprivation that you experienced during the first 24 hours will intensify. This includes fatigue, irritability, drowsiness, impaired vision and hearing, lack of good judgment, and cognitive impairment. Your reaction time will be significantly slower, and you may have difficulty speaking.

Research has shown that 36 hours without sleep can cause an increase in appetite and a desire for foods associated with weight gain. However, consuming these types of foods can make you feel even more tired. It is recommended that you opt for lean, protein-rich foods such as nuts, nut butters, cottage cheese, or tofu.

After 48 hours: microsleeps and impaired immune system

After 48 hours without sleep, most people will experience microsleep episodes and an impaired immune system. Microsleeps are brief periods of sleep that can last anywhere from a few seconds to 30 seconds. During microsleep, a person may nod off or keep their eyes open and appear awake, but their brain is not processing external information as it usually would. They may experience lapses in attention, slowed eye movements, and a reduced response to external stimuli. These episodes are often followed by feelings of confusion and disorientation.

Microsleeps commonly occur when individuals are sleep-deprived, but they can also happen to well-rested individuals engaged in monotonous tasks, such as driving on an empty highway or attending a lecture. They pose a significant risk when performing tasks that require constant alertness, such as driving or operating heavy machinery. In fact, drowsy driving is responsible for over 1,550 fatalities and 40,000 non-fatal injuries in the United States each year.

On the immune side, 48 hours of sleep deprivation is associated with increased levels of inflammatory markers, which are proteins that signal the body to promote inflammation in response to illness or injury. Specifically, this duration of sleep loss has been linked to decreased activity of natural killer (NK) cells, which play a crucial role in defending the body against viruses and bacteria. This reduction in NK cell activity can leave individuals more susceptible to infections and illnesses.

In summary, going without sleep for 48 hours can lead to microsleep episodes, which can be dangerous in certain situations, and can impair the immune system, making individuals more vulnerable to health threats.

After 72 hours: complex hallucinations and distorted reality

After 72 hours without sleep, your perception of reality will be severely distorted, resembling acute psychosis. Your urge to sleep will be unbearable, and you will likely experience microsleep, which is a protective reflex from the brain that forces you to fall asleep for a brief moment. These microsleep episodes can last up to 30 seconds, and you may not even be aware that they are happening.

At this stage, your ability to interpret your surroundings and read others' emotions will be compromised. You may experience complex hallucinations and illusions, which are a misinterpretation of something that is real. For example, you may struggle to read other people's emotions or have difficulty determining whether something you see is human.

Research has shown that staying awake for 72 hours can contribute to an increased heart rate, extreme mood swings, and a reduced ability to process information. Additionally, your ability to regulate your emotions will be severely compromised, and you may become irritable, anxious, or depressed. You may also struggle with executive functioning and thinking, and your perception of reality may be severely distorted.

It is important to note that the effects of sleep deprivation at this stage can be severe and may take several days or even weeks to fully recover.

After 96 hours: severe psychosis

After 96 hours of sleep deprivation, an individual's perception of reality may be severely distorted, resembling acute psychosis. The urge for sleep will also feel unbearable.

At this stage, the individual will experience a host of symptoms, including:

• Complex hallucinations: The individual may experience hallucinations in all three sensory modalities—visual, somatosensory, and auditory. These hallucinations may become more complex and persistent over time.
• Delusions: The individual may develop delusions, such as feelings of persecution or paranoia, delusions of control, grandeur, or jealousy, and primary delusions. These beliefs may be firmly held and elaborated upon.
• Mood changes: The individual may exhibit signs of anxiety, irritability, anger, hostility, apathy, depression, or euphoria. They may also become more easily irritated and experience changes in their mood.
• Disordered thoughts and confusion: The individual may have difficulty forming thoughts, finding words, and composing sentences. They may experience fragmented thinking, memory loss, and confusion.
• Dissociation and depersonalization: The individual may feel detached from their body, as if they are observing themselves from a distance. They may question their sense of self and reality.
• Temporal disorientation: The individual may have a distorted sense of time, feeling that time is passing slowly or is a "hodgepodge."

It is important to note that the effects of sleep deprivation can vary depending on individual factors, and the above symptoms may not occur in a fixed order or with the same intensity for everyone. Additionally, the duration of sleep deprivation required to experience severe psychosis may differ from person to person.

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