At some point in your life, you’ve likely pulled an all-nighter and stayed up ‘til dawn. Or maybe you’ve had a series of rough nights, only getting a couple of hours of shut-eye over the span of a few days. During the depths of your exhaustion, you’ve probably wondered: is lack of sleep dangerous? In this article, we’ll break down what we know about sleep and survival.
Do You Need Sleep to Live?
We may not fully understand the mechanisms of sleep, but we do know this for sure: you need sleep to survive. Sleep is an essential function for both your body and mind.
One reason humans need sleep is for brain plasticity. As explained by Medical News Today: “During the day, synapses switch on in response to the stimuli that the brain receives from the environment. But during sleep, the activity of these synapses goes back to normal. Without this restorative period, they stay excited at their peak activity for too long. This interferes with the brain’s neuroplasticity—that is, its ability to re-wire itself and create new connections between neurons. Neuroplasticity enables the brain to ‘pick up’ new skills, change and adapt to its environment stimuli, and ultimately learn new things.” You also need sleep to unlearn information that isn’t important and to flush the brain of toxins and waste.
Plus, sleep is essential to physical health. You need it for growth, muscle repair, immune system function, cardiovascular health, maintaining a healthy metabolism, healing from injuries, and more.
How Long Can Humans Stay Awake?
In 1963, 17-year-old Randy Gardner stayed awake for 264 hours (11 days), breaking the record for the longest continuous period without sleep. But don’t try this yourself. The Guinness Book of World Records no longer includes a record for staying away awake because of the health risks.
A better question is: how much sleep do you need to stay healthy? The Centers for Disease Control and Prevention (CDC) recommends seven or more hours of sleep a night for adults ages 18 to 60. Head to their website for more information and guidelines for other age groups.
What Are the Risks of Sleep Deprivation?
Acute lack of sleep and long–term sleep deprivation can both take a toll on your mental and physical health. Below, we’ve outlined the dangers and side effects of deficient sleep.
Short-Terms Side Effects of Sleep Deprivation
- Lack of sleep can cause stress, irritability, and mood instability.
- Sleep deprivation can lead to drowsiness and deficits in memory, cognition, concentration, reaction time, and performance. It can also cause headaches and hallucinations.
- Lack of sleep can put you and others at risk of accidents and injury, especially if you drive. According to the CDC, “Being awake for 17 hours is similar to having a blood alcohol concentration (BAC) of 0.05 percent (the level some countries use for drunk driving violations). Being awake for 24 hours is similar to having a BAC of 0.10 percent (above the U.S. drunk driving level of 0.08.” Do not drive drowsy or sleep-deprived.
Long-Terms Risks of Sleep Deprivation
- Chronic sleep deprivation increases the risk of weight gain, kidney disease, diabetes, high blood pressure, stroke, other cardiovascular diseases, and depression.
How Many Nights Can You Go Without Sleep?
As previously mentioned, the world record for staying awake is 11 days. That said, you would likely feel the ill effects of sleep deprivation much sooner. Below, we examine a few studies on how humans react to long hours without rest.
24 Hours Without Sleep
For this 2022 study, 12 females completed two computerized tests after a normal night of sleep and after 24 hours without sleep. They completed an object hit and avoid (OHA) task and a go/no-go (GNG) task to assess recognition of shapes and emotional facial expressions. When sleep-deprived, they performed worse on both exams.
36 Hours Without Sleep
A 2020 study involving 16 male students found that 36 hours without sleep impaired their working memory ability and decreased speed in processing information.
72 Hours Without Sleep
This 2015 study compared the effects of 72 hours of sleep deprivation to 72 hours of social isolation on 12 healthy male astronauts. The experiment showed impaired cognition, higher heart rate, and an increase in negative mood for the sleep-deprived participants.
What Is Fatal Familial Insomnia (FFI)?
Fatal familial insomnia (FFI) is extremely rare, affecting fewer than 1,000 people in the United States. This genetic disease affects the thalamus, which controls sleep-wake cycles. It can cause sleep disturbance, psychiatric symptoms, mood changes, high blood pressure, weight loss, imbalance, and dementia. Symptoms worsen rapidly; on average, patients with FFI live 18 months after onset.
What Are the Consequences of Oversleeping? Can Too Much Sleep Kill You?
On the other end of the spectrum, you may wonder if too much sleep can do you harm. Like sleep deprivation, oversleeping has its risks. According to Johns Hopkins Medicine, oversleeping is linked with type 2 diabetes, heart disease, obesity, depression, and headaches. Hopkins professor Vsevolod Polotsky explains that regularly sleeping more than eight to nine hours a night could signify an underlying condition, such as sleep apnea or narcolepsy. Talk to your doctor If you suspect oversleeping is affecting your physical or mental well-being.
Putting Sleep Deprivation to Rest
If you struggle to get at least 7 hours of sleep each night, it may be time to make some behavioral or environmental changes.
Talk to your doctor about treating underlying conditions and lifestyle changes you can make to strengthen your circadian rhythms. A few common ways to improve sleep include following a regular sleep schedule, exercising daily, eating a healthy diet, and getting plenty of natural sunlight. Your doctor may also suggest supplements, medications, or cognitive behavioral therapy for insomnia.
You can also make improvements to your bedroom environment to support healthy, uninterrupted sleep. You need a dark, quiet bedroom and a supportive mattress that cushions your joints and keeps your spine aligned. The more comfortable you are, the easier it is to relax and drift off to sleep.