Sleep Deprived? Here Is What Lack of Sleep Does to Your Body

Nearly half of US adults say they do not get enough sleep.

Sleep isn’t a luxury—it’s a biological necessity. Yet in a world that glorifies hustle and constant connectivity, too many of us are running on empty. Whether it’s late nights at the office, chronic stress, or everyday lifestyle habits, sleep deprivation has quietly become a public health crisis.

The consequences go far beyond feeling groggy. Sleep loss affects everything from focus and mood to long-term heart health and immune function. But the good news? Once we understand what’s stealing our rest, we can begin to take it back.

In this guide, we’ll uncover the leading causes of sleep deprivation, its toll on both mind and body, and the science-backed steps you can take to reclaim your well-being—starting tonight.

What is Sleep Deprivation?

The designation of sleep deprivation is straightforward: A person who doesn’t get enough sleep. People are considered sleep deprived whether the lack of sleep lasts one night or several months. The first step to avoiding sleep deprivation is to follow the guidelines for your age group as follows:

Newborns (up to 3 months old): 14 to 17 hours
Infants (4 to 12 months old): 12 to 16 hours, including naptime
Young children (1 to 5 years old): 10 to 14 hours, including naptime
School-aged children (6 to 12 years old): 9 to 12 hours
Teenagers (13 to 18 years old): 8 to 10 hours
Adults (18 years and up): 7 to 9 hours

FAST STAT: 33% Increase in Dementia Risk

Why Am I Sleep Deprived?

Sleep deprivation is so common that most people experience it at least once, if not several times, in their lives. It can happen for a variety of reasons, such as:

Alcohol use or abuse
Poor sleep hygiene
Shift work
Sleeping somewhere other than your home
Stress
Using stimulants too close to bedtime

Certain medical conditions can cause sleep deprivation as well. These include:

Common cold and flu
Depression or anxiety
Dementia, Alzheimer’s disease or Parkinson’s disease
Insomnia
Parasomnias
Restless Leg Syndrome (RLS)
Sleep apnea
Type 2 diabetes

Getting enough sleep if you’re being treated for any of the above conditions is essential to prevent further damage to your health. If you suspect you might be sleep deprived, it’s important to consult your physician for the necessary support and guidance.

FAST STAT: 1 in 25 Adults Have Fallen Asleep at the Wheel in the Past Month

Immediate Effects of Not Sleeping Enough

It only takes one sleepless night to feel sleep deprived. The first noticeable signs of sleep deprivation impact your cognitive abilities and emotions.

Researchers agree that the lack of sleep slows response speed and negatively impacts alertness, attention, and vigilance. However, some studies show that sleep deprivation also leads to problems with high-level cognitive abilities such as perception, memory, and executive function.

In addition, sleep deprivation can play havoc on your emotions. You’re more likely to respond negatively to stressful situations and feel less positive about the good things in life. Essentially, sleep deprivation puts you in a bad mood no matter what. You might also become more irritable or experience symptoms of depression or anxiety.

FAST STAT: 3X more likely to catch a cold

Physical Effects of Lack of Sleep

Sleep deprivation challenges your body’s systems that help you stay physically healthy. Lack of sleep can lead to a less active immune system, making you more susceptible to illness.

You can also experience hormonal imbalances that affect your appetite and prevent you from having a healthy weight. Lack of sleep can cause higher levels of ghrelin, which makes you feel more hungry. On the flip side, lower levels of the appetite hormone leptin can make you feel less hungry.

Your cardiovascular system can be compromised, causing elevated blood pressure and increased heart rate, leading to myriad health concerns, including hypertension.

FAST STAT: Lack of sleep can age your brain by 3-5 years

Sleep Deprivation and Mental Health

More than 50 years of research shows that sleep deprivation negatively impacts mental health as well. A study published by the American Psychological Association analyzed data from 154 studies with 5,715 total participants and found that the lack of sleep put participants at a higher risk of experiencing anxiety and depression symptoms.

Researchers in the studies disrupted the participants’ sleep for one or more nights in three different ways:

Keeping participants awake later than usual
Allowing participants to sleep less than usual
Periodically waking participants up throughout the night

Regardless of the type of sleep loss, researchers determined participants experienced fewer positive emotions the next day and reported increased symptoms of anxiety, including increased worrying and rapid heart rate.

The results from the combined studies show that more than 30% of adults and up to 90% of teenagers don’t get enough sleep, according to the study’s lead author, Dr. Cara Palmer of Montana State University. She advises that people whose job makes them prone to sleep deprivation, such as first responders, pilots, and truck drivers, should prioritize sleep to protect their well-being and prevent lapses in daytime function. John Hopkins Medicine reports that 6,000 fatal car crashes are caused by tired drivers each year.

FAST STAT: 48% increased risk of developing heart disease

Long-term Consequences of Chronic Sleep Deprivation

Harvard Medical School recommends “treating sleep as a priority, rather than a luxury” to help prevent chronic medical conditions. The school’s Division of Sleep Medicine longitudinal epidemiological studies show that long-term sleep habits are associated with the development of diseases. Participants who were considered healthy at the beginning of the long-term studies showed signs of developing or having diseases. The studies showed that the most common chronic diseases were:

Type 2 Diabetes: Adults who consistently sleep less than five hours per night have an increased risk of having or developing diabetes.
Obesity: Adults who sleep less than five hours per night have a 50% higher risk for obesity.
Heart Disease and Hypertension: Lack of inadequate sleep for one night for people with diagnosed hypertension raises blood pressure the next day. Women who sleep less than six hours or more than nine hours a night have an increased risk of heart disease.
Life Expectancy: Sleeping less than five hours per night increases the mortality risk by 15%—from all causes.

Your physician or a sleep specialist should treat sleep deprivation as quickly as possible to prevent long-term adverse effects and chronic conditions.

Tips for Preventing Sleep Deprivation

Good practices and habits that affect your ability to fall and stay asleep, or sleep hygiene, are the best ways to prevent sleep deprivation. By incorporating better habits into our daily routine, we can take a proactive role in maintaining our health and well-being.

From cutting out your late cup of coffee to turning off your smartphone in the evening, small habits to incorporate into your daily life can help you establish good sleep hygiene practices, such as:

Establish a bedtime routine with calming activities like reading or listening to music
Do light yoga or stretching before bed
Avoid heavy meals in the evening
Choose healthy evening snacks
Turn off all devices one to two hours before bedtime
Don’t force yourself to sleep

In addition to good sleep hygiene, a comfortable and relaxing sleep environment can contribute to better sleep. Try incorporating these tips to turn your bedroom into a calm, soothing oasis:

Declutter your space
Incorporate Feng Shui
Repaint with soothing colors
Bring nature indoors with houseplants
Try a white or pink noise machine
Listen to relaxing playlists or guided meditation apps
Use essential oils like lavender, cedarwood, and bergamot in a diffuser
Accessorize with bedding and pillows

Perhaps most importantly, if you’ve been sleeping on the same mattress for over seven years, it’s time for a replacement. Make a plan to go mattress shopping, and use our S.L.E.E.P. Test as your guide: