Sleep Deprivation: Is 5 Hours Enough?

Sleep is essential for physical and mental health, but many people don't get enough of it. While the demands of modern life can get in the way, regularly sleeping for only five hours a night may lead to sleep deprivation and have serious health effects. So, is five hours of sleep enough?

Sleep deprivation

Sleep is essential for good physical and mental health, but many people do not get enough of it. While most adults need between seven and nine hours of sleep, some average five or fewer hours per night.

Regularly getting only five hours of sleep can lead to sleep deprivation and have serious health effects. Short-term cognitive changes include difficulty concentrating, remembering things, and slower reaction times. Sleep deprivation can also increase the likelihood of serious accidents, as it impairs functioning in a similar way to having a blood alcohol content of 0.08%.

In the long term, people who sleep less than six hours per night have a higher incidence of high blood pressure, heart attacks, stroke, heart disease, kidney disease, and diabetes. Research has also shown that sleep deprivation is associated with an increased risk of psychiatric illnesses, including depression, anxiety, bipolar disorder, and neurological diseases like Alzheimer's.

To improve sleep quality, it is recommended to limit time on devices and avoid screens for 30 minutes to an hour before bedtime, as blue light can delay your circadian rhythm. Substances like caffeine and alcohol can also delay or disrupt sleep, especially when consumed too close to bedtime. Prioritizing sleep, exercising regularly, and maintaining a balanced and nutritious diet can all help promote healthy sleeping habits.

Short-term cognitive changes

Sleep is essential for our health and happiness. Consistently getting less than 5 hours of sleep can have adverse effects on both physical and mental health. In the short term, sleep loss may negatively affect the immune system and the body's ability to fight disease.

Excessive Sleepiness

Drowsiness and fatigue are common daytime effects of a night of poor sleep. In response to excessive fatigue, a person may inadvertently nod off for a few seconds, which is known as a microsleep. This can be extremely dangerous if it occurs while driving or operating heavy machinery.

Poor Attention Span

Poor sleep reduces a person’s attention, as well as their learning and processing abilities. Lack of sleep has also been found to induce effects similar to being drunk, which slows down thinking and reaction time. Poor sleep also diminishes placekeeping, which includes the ability to carry out instructions.

Reduced Adaptability

Some studies have found a lack of sleep to hinder cognitive flexibility, reducing the ability to adapt and thrive in uncertain or changing circumstances. A major reason for this is rigid thinking and "feedback blunting", where the capacity to learn and improve on the fly is diminished.

Reduced Emotional Capacity

Poor sleep can also alter how emotional information is understood. When learning something new, analyzing a problem, or making a decision, recognizing the emotional context is often important. However, insufficient sleep impedes the ability to properly process the emotional component of information.

Impaired Judgment

In some cases, this dysregulated emotional response impairs judgment. People who do not get sufficient sleep are more likely to make risky choices and may focus on potential rewards rather than downsides. It can be difficult to learn from these mistakes since the normal method of processing and consolidating emotional memory is compromised due to a lack of sleep.

Health impacts

Cognitive Functioning

Sleeping only five hours a night can have a negative impact on cognitive functioning. Lack of sleep makes it harder to concentrate, increases reaction times, and makes it more difficult to reason through complex tasks. Sleep is also important for learning and memory, as it is believed that new information is integrated into memory during sleep.

Mood and Mental Health

Not getting enough sleep can make people more irritable and less able to manage their emotions and deal with stress. Sleep deprivation has been linked to an increased risk of psychiatric illnesses, including depression, anxiety, and bipolar disorder, as well as neurological diseases like Alzheimer's. Research has also found a link between long-term sleep loss and the development of mental health conditions like depression and anxiety.

Greater Risk of Accidents

Sleep loss negatively impacts concentration and reaction time, increasing the risk of errors and accidents. One of the most dire consequences of sleep deprivation is drowsy driving, which is a major contributor to car accidents.

Physical Health Impacts

Sleep deprivation can have long-term impacts on physical health. It is a risk factor for cardiovascular health issues like high blood pressure, stroke, and heart disease, as well as type 2 diabetes and kidney disease. In the short term, sleep loss may negatively affect the immune system and the body's ability to fight disease.

Quality of Life

Lack of sleep can impact overall quality of life, as people are less likely to engage in activities they enjoy due to low energy levels. Feeling excessively tired or falling asleep unexpectedly at home or work can also affect a person's career, relationships, and create tension among peers.

Sleep quality

Sleep Latency and Efficiency

Sleep latency refers to how long it takes for someone to fall asleep. A healthy sleep latency is typically around 15 to 20 minutes. Sleep efficiency, on the other hand, describes the proportion of time spent in bed that is actually spent sleeping. A healthy sleep efficiency score is considered to be around 85%. These two factors play a significant role in determining the quality of sleep.

Nighttime Awakenings

Frequent awakenings during the night can be a sign of sleep fragmentation and poor sleep quality. This can disrupt the sleep stages and impact overall restfulness.

Sleep Stages

Impact on Health

Poor sleep quality can have significant health consequences. It can increase the risk of accidents, affect cognitive functioning, and lead to irritability and mood changes. Additionally, chronic sleep deprivation has been linked to various physical health issues, including heart and kidney problems, as well as mental health concerns such as depression and anxiety.

Subjective Nature of Sleep Quality

It's important to note that sleep quality is partially subjective. It depends on how rested an individual feels when they wake up and throughout the day. Some people may feel well-rested with less sleep, while others may require more sleep to function optimally.

Improving Sleep Quality

To enhance sleep quality, it's recommended to establish a consistent bedtime schedule and routine, avoid electronics before bed, limit substance use, and prioritize sleep as an essential aspect of overall health and well-being.

Sleep disorders

Five hours of sleep is not enough for most adults, who need between seven and nine hours of sleep per night for optimal health. Consistently getting less than five hours of sleep can have adverse effects on both physical and mental health.

Insomnia

Insomnia is the most common sleep disorder. It involves difficulty falling and staying asleep. About one-third of adults report symptoms of insomnia, and 4-22% meet the criteria for insomnia disorder. It can be treated with a combination of sleep medications and behavioural techniques, such as cognitive-behavioural therapy.

Sleep Apnea

Sleep apnea is a breathing disorder characterised by episodes of reduced or no airflow during sleep. It is associated with serious medical problems, including cardiovascular disease and diabetes. It can be treated with a CPAP (continuous positive airway pressure) machine.

Restless Leg Syndrome (RLS)

RLS involves a tingling or prickly sensation in the legs, along with a powerful urge to move them. It can be caused by genetic factors and is treated with medication.

Hypersomnia

Hypersomnia is characterised by an inability to stay awake during the day. This includes narcolepsy, which causes extreme daytime sleepiness.

Circadian Rhythm Disorders

Circadian rhythm disorders are problems with the sleep-wake cycle, making it difficult to sleep and wake at the right times. They can be caused by internal factors, where a person's body clock is different from the light-dark cycle, or external factors, such as shift work or jet lag.

Parasomnia

Parasomnia involves acting in unusual ways while falling asleep, sleeping, or waking from sleep, such as walking, talking, or eating.

Frequently asked questions