The Dangers Of Sleep Deprivation: 48 Hours Without Sleep

Sleep is essential for maintaining physical, mental, and emotional health. Sleep deprivation can have serious consequences, and the effects of going without sleep for 48 hours can be severe. After two nights without sleep, most people experience difficulty staying awake, with periods of light sleep or microsleeps that can last up to 30 seconds. This level of sleep deprivation can lead to an overwhelming urge to sleep, impaired thinking, and altered perception, including hallucinations and illusions. It can also impact emotions, with people experiencing irritability, anxiety, paranoia, and even depression. Going without sleep for 48 hours can also disrupt the immune system, increasing the risk of illness and infection. While the short-term effects of sleep deprivation may resolve after getting enough sleep, chronic sleep deprivation can have long-term health complications, including an increased risk of high blood pressure and certain cancers.

Increased risk of accidents and impaired coordination

Sleep deprivation can have serious consequences, and the longer a person goes without sleep, the more severe these consequences become. After two days without sleep, a person will experience extreme sleep deprivation, with a range of adverse effects on their health and coordination.

After 48 hours without sleep, a person will experience "extreme sleep deprivation". At this point, the body starts to shut down for "microsleeps", which are 3- to 15-second bursts of rest during which the brain switches off. A person may not be consciously aware that they are experiencing microsleep, but their brain is going offline for several seconds at a time. This can be incredibly dangerous, especially if the person is driving, operating heavy machinery, or making important decisions.

Research has shown that after two days without sleep, a person's coordination is severely impaired. A small study published in the Journal of Sleep Research in 2016 found that 29 healthy young men who were kept awake for 24 hours were more likely to recall false memories. This indicates that sleep deprivation can significantly impair a person's judgment and decision-making ability.

In addition to impaired coordination, a person who has been awake for 48 hours is likely to experience increased irritability, anxiety, and foggy memory. They may also have trouble forming thoughts and sentences.

The effects of sleep deprivation can be compared to the cognitive impairment caused by alcohol intoxication. According to the Centers for Disease Control (CDC), staying awake for 24 hours is similar to having a blood alcohol concentration of 0.10%, which is higher than the legal limit for driving in the US. As a result, a person who has been awake for two days is at a significantly increased risk of accidents.

Heightened stress hormones

Sleep deprivation and stress are closely linked. Sleep loss can cause a rise in the stress hormone cortisol, which is produced by the hypothalamic pituitary adrenal (HPA) axis. Cortisol is best known for its role in the stress response, and cells all over the body are studded with cortisol receptors.

Sleep deprivation can cause an increase in the activity of the HPA axis, leading to a rise in circulating levels of stress hormones. This increase in HPA axis activity can disrupt sleep cycles, causing shortened overall sleep time. These sleep disturbances can further affect the HPA axis, distorting the body's production of cortisol.

The HPA axis and sleep share the same pathway, so when something disrupts the HPA axis, it can also disrupt sleep cycles. Sleep isn't a steady state; the body goes through various stages of sleep each night. Non-REM sleep has three stages, and REM sleep is the part of the sleep cycle when we have vivid dreams. A sleep cycle lasts about 90 minutes, and during that time, we move through these four stages of sleep. Most of our deeper slow-wave sleep happens in the first half of the night, while REM sleep happens more during the second half of the night.

The effects of sleep deprivation on cortisol levels can vary. Some studies have shown that moderate sleep loss has modest effects on HPA axis activity, with endogenous compensatory mechanisms during sleep keeping cortisol levels stable. However, greater sleep loss has been associated with increased afternoon and evening cortisol levels and reduced reactivity and slower recovery of the cortisol response.

Cortisol has a powerful influence on sleep and waking in the human body. It can also influence digestion and metabolism and help the immune system to function in response to illness or injury.

If you're having sleep issues, you could try modifying your diet to eliminate cortisol-triggering foods, taking fish oil and ashwagandha supplements, exercising regularly at a moderate intensity, and practising mindfulness and meditation.

Cognitive impairment

Sleep deprivation can have a significant impact on cognitive function, and the effects worsen the longer a person goes without sleep. After just 24 hours without sleep, an individual may experience impaired coordination, short-term memory loss, brain fog, and problems with social cues. They may also have trouble concentrating and performing complex tasks.

At 36 hours of sleep deprivation, cognitive impairment becomes more severe. Individuals may feel sluggish and experience delayed reaction times, foggy memory, and an inability to concentrate, learn new information, or process social cues. They may also have difficulty thinking creatively and experience illusions or simple visual hallucinations.

After 48 hours without sleep, symptoms of extreme sleep deprivation set in, including switches between feelings of apathy and euphoria, auditory disturbances, and feelings of being outside one's body. Individuals may also encounter hallucinations and have trouble forming thoughts and sentences.

By 72 hours of sleep deprivation, individuals may experience significant deficits in concentration, motivation, perception, and other higher mental processes. They may also have complex visual and auditory hallucinations, delusions, and paranoia. The mind is ripe for hallucinations and delusions, and the body starts to compensate by shutting down for "microsleeps", which are brief periods of rest where the brain switches off for a few seconds.

Mood changes and hallucinations

Sleep deprivation can cause a range of mood changes and hallucinations, which can be dangerous and frightening. After 24 hours without sleep, you may feel tired, exhausted, and "off". After 36 hours, you will have an overwhelming urge to sleep and may experience microsleeps. After 48 hours, you will be even more likely to experience microsleeps, as well as perceptual distortions, increased irritability, and temporal disorientation.

The longer a person goes without sleep, the more severe their symptoms are likely to be. After 72 hours without sleep, your urge to sleep will strengthen and may become uncontrollable. Your hallucinations may become more complex, and you may experience a severe distortion of your perception of reality, resembling acute psychosis.

Mood changes are common with sleep deprivation. Studies have shown that people who are sleep-deprived report increases in negative moods such as anger, frustration, irritability, and sadness, as well as decreases in positive moods. Sleep loss can also impair judgement and impact physical coordination, making everyday tasks more difficult and increasing the risk of accidents.

Hallucinations are also a common symptom of sleep deprivation. These can be frightening and may involve seeing, hearing, tasting, smelling, or touching something that is not there. Auditory hallucinations are the most common type, but visual hallucinations are also frequently reported. Hallucinations typically begin to occur after one or two nights without sleep, and they become more complex and persistent as sleep deprivation continues.

Health complications

Sleep deprivation can have serious health implications, and the longer a person goes without sleep, the more severe these effects will be. After two days without sleep, a person will be experiencing extreme sleep deprivation.

48 Hours Without Sleep

After two days without sleep, a person will be suffering from extreme sleep deprivation. At this point, a person is likely to experience symptoms of depersonalisation and derealisation—problems with accurately perceiving oneself and reality.

Other symptoms include:

• Fluctuating between feelings of apathy and euphoria
• Auditory disturbances, such as an inability to locate the source of a sound
• Feeling as though one is outside of one's body
• Difficulty forming thoughts and sentences
• Increased irritability, anxiety, and impaired thinking
• Memory issues
• Hallucinations

72 Hours Without Sleep

After three days without sleep, a person will experience a severe decline in mental health, with symptoms including:

• Complex visual hallucinations
• Auditory hallucinations
• Delusions
• Slurred speech
• Unsteady walking
• A fragile emotional state
• Paranoia
• A loss of touch with reality

Short- and Long-Term Effects of Sleep Deprivation

Short-term effects of sleep loss can include:

• A higher chance of injuries, accidents, and reckless risk-taking
• Impaired judgement
• Reduced performance at work or school
• Problems with interpersonal relationships
• Higher pain sensitivity
• Mental health issues, such as stress, anxiety, and worsening of existing mental health conditions
• A weakened immune system
• A lowered quality of life

Chronic sleep deprivation can have long-term health complications, increasing the risk of:

• High blood pressure (hypertension)
• Certain cancers, such as colorectal cancer
• Obesity
• Heart disease
• Diabetes
• Kidney disease
• Stroke

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