12 Signs of Sleep Deprivation You Need to Know

When you feel sluggish, weak, and unproductive, you may be sleep deprived. It's important to address sleep deprivation and get sleep cycles back on track.

According to the Centers for Disease Control and Prevention (CDC), about 1 in 3 adults in the United States reported not getting enough rest or sleep every day. And not getting enough sleep is linked with many chronic diseases and conditions—such as type 2 diabetes, heart disease, obesity, and depression.

Here, experts explain 12 different signs and symptoms of sleep deprivation.

You're Always Hungry

"If the brain is not getting the energy it needs from sleep, it will often try to get it from food," said Chris Winter, MD, owner of Charlottesville Neurology and Sleep Medicine in Virginia. Running low on rest can increase the production of ghrelin. Though it's known as the hunger hormone, ghrelin also helps improves survival after a heart attack and prevents muscle atrophy, among other functions, according to a 2014 study published in Current Opinion in Clinical Nutrition and Metabolic Care.

Too much ghrelin makes your body crave fatty and sugary foods, said Dr. Winter. Poor sleep can also mess with leptin, the satiety hormone. "When you're not sleeping properly you tend to eat more of what you're craving because you're not feeling the signals to stop eating," he said.

You've Gained Weight

With an increased appetite comes another unpleasant symptom of sleep deprivation: weight gain. "When you're tired, you don't watch what you're eating," said Dr. Winter. "You just look for all kinds of things to help you feel more awake."

With ghrelin and leptin already out of whack, your body may crave fried foods and sweets—a surefire way to widen your waistline. A lack of sleep may also have direct effects on your metabolism, said Dr. Winter. Your metabolism tends to slow down without proper rest. A 2021 meta-analysis published in Nutrition Reviews found that short sleep duration was associated with incidence of obesity.

You're More Impulsive

People tend to act without thinking when they're exhausted, said Gail Saltz, MD, Health's contributing psychology editor. "Your ability to say, 'No, I shouldn't have another candy bar' becomes more difficult."

This doesn't just apply to eating more—you might also find yourself doing or saying things you don't necessarily mean, like lashing out at a spouse or ranting at a coworker. "The main thing is you're less inhibited," said Kelly Baron, PhD, a clinical psychologist with specialty training in behavioral sleep medicine.

A 2022 study in Behavioural Brain Research points out that sleep deprivation impairs memory, inhibition, cognitive flexibility, and attention.

Also, a Sleep Health study published in 2016 found that, among urban youth, individuals reporting longer sleep duration were significantly less likely to report moderate physical aggressive behavior against peers.

Your Memory Is Shot

If you grew up being told not to stay up late the night before a big test, your parents knew what they were talking about. A 2016 study in Science Signaling showed that sleep deprivation has a negative impact on memory function.

Specifically, being overtired stops protein synthesis from occurring in the hippocampus section of the brain, which controls memory, learning, and emotions. According to a 2012 report by the journal of Behavioural Brain Research, sleep deprivation induces oxidative stress (an imbalance between free radicals and antioxidants in your body), which further impairs learning and memory processes. The study authors demonstrated that using Vitamin E, which is a strong antioxidant, counteracted the negative impact of sleep deprivation on memory function (also referred to as chronic sleep deprivation-induced cognitive impairment).

You're Having Trouble Making Decisions

If you've been finding it harder than usual to manage projects at work and home, lack of sleep could be the culprit. "Sleep deprivation can affect speed and higher-level cognitive processing," said Dr. Baron. That means essential functions, such as problem-solving or time management, become even more difficult to carry out.

A lack of sleep may also affect your financial decisions. A 2015 study in the journal Frontiers in Neuroscience looked at how one night of total sleep deprivation could alter economic choices. The study authors found that sleep deprivation negatively impacted decision-making and led to lost gains.

Your Motor Skills Are Off

We all trip from time to time. But if you do it a few times in one day, you may be too tired to focus on where you're going.

A 2014 study published in Neurobiology of Learning and Memory found that acute sleep deprivation negatively affected "motor and reversal learning and memory." Translation: "When you're tired, there's a lapse in how you neurologically function in general," said Dr. Winter. With lowered reaction time and concentration also comes more difficulty with movement. "When you walk up and down the stairs, there's a lot of processing going on there," he said. "When sleep-deprived, you can't process particularly well."

Your Emotions Are All Over the Place

You may feel as if your emotions are out of control when you've missed sleep. "You become over-reactive to emotional stimuli," said Dr. Baron. So, things that normally haven't gotten you worked up in the past—a tear-jerking movie or big work deadline—may provoke anxiety, sadness, or anger. (It could also go the opposite way: "People can get slap-happy and giddy as well," she said.)

A 2018 Cureus review of literature found that individuals who get an adequate amount of sleep each night exhibit fewer emotional outbursts, such as anger, and display fewer aggressive behaviors.

You Get Sick Often

Your immune system can suffer with poor sleep too. "There can be significant issues in terms of your body's ability to fight off infections," said Dr. Winter. In particular, you may find that it's harder to shake off a cold.

A 2015 study in Sleep followed 164 healthy men and women over seven consecutive days. Participants were quarantined, given nasal drops containing the rhinovirus, and monitored over five days for the development of a cold. The study found that shorter sleep duration was associated with increased susceptibility to the common cold.

While you sleep, your immune system produces cytokines, which are proteins that help protect against infections and inflammation. Researchers suspected that a few nights of poor sleep could lower your body's production of cytokines, thereby weakening its defenses against viruses.

You're Having Trouble Seeing

"When fatigued, you're not able to control the muscles of the eye as well (as you usually do)," said Steven Shanbom, MD, an ophthalmologist in Berkley, Michigan. First, skimping on sleep tires out the ciliary muscle, which helps your eyes focus. The result: you'll have a harder time reading up close, he said.

Then there's the extra ocular muscle, which moves the eye from side to side and up and down. "Many people have a muscle imbalance where their eyes don't track well together," Dr. Shanbom told Health, but in a well-rested person the eyes can compensate on their own. A lack of sleep makes the misalignment harder to control, potentially resulting in double vision. You may notice both of these vision problems after one night of poor sleep, and they may persist the less time you spend in bed.

Your Skin Isn't Looking Good

Of all the places on your body, your face can truly show your age if you don't take steps to keep your skin healthy. Those steps include common precautions such as maintaining a well-balanced diet rich in good fats, using UV protection, and yes, even getting a good night's sleep. In a 2014 Clinical and Experimental Dermatology study, experts found that poor sleepers had higher levels of transepidermal water loss, aging their skin more than good sleepers. Additionally, good sleepers had 30% greater skin barrier recovery. They also had a better perception of their appearance and physical attractiveness compared to poor sleepers.

"When a good night's sleep is hindered, you will look significantly more fatigued," said Flora Kim, MD, FAAD, of Flora Kim Dermatology in Dallas, Texas. Dark under-eye circles, saggy eyelids, wrinkles or fine lines, droopy corners of the mouth, and paler skin may result. She said sleep deprivation can also cause occasional acne due to circadian disruption, which translates to an abrupt biological change that creates an imbalance in your skin.

People with sleep deprivation tend to offset their fatigue with increased caffeine intake and/or smoking, both of which can contribute to occasional acne. "Your body (also) produces collagen while you're sleeping," said Dr. Debra Jaliman, MD, a board-certified dermatologist and assistant clinical professor of dermatology at the Icahn School of Medicine at Mount Sinai in New York City. "Getting enough sleep helps skin restore itself," she said. "The cells regenerate, and DNA repair is also boosted during this period."

You Think You've Fallen Asleep at the Wheel

When you nod off for a few seconds without even knowing, you may be experiencing microsleep. "The brain says, 'I don't care what you want to do. We are going to sleep,'" said Dr. Winter. It's your body's way of forcing you to get the rest you need. The big problem is that microsleep can be extremely dangerous if you happen to be driving. The National Highway Traffic Safety Administration estimated that in 2017, 91,000 police-reported crashes involved drowsy drivers. These crashes led to an estimated 50,000 people injured and nearly 800 deaths.

If you ever feel overly sleepy on the road, pull over and rest until you feel up to taking the wheel again.

You're Not Growing

Adequate sleep and successful growth go hand and hand. That's why babies sleep so much during their first few years; their bodies are undergoing rapid growth. The trend continues into childhood and adolescence, according to a 2014 study published in Nursing Management. Generally, children ages 5 to 10 years old need 10 to 11 hours of sleep, and those ages 10 to 17 need about eight to nine hours, the research concluded.

"The human growth hormone (HGH) kicks in while we are sleeping," said Dr. Jaliman, who added that HGH is also responsible for speeding up skin's repair and cell regeneration.

Compared to awake levels, circulating concentrations of growth hormones elevate significantly while you're sleeping, according to a 2010 study in the Journal of Clinical Endocrinology & Metabolism. So, a lack of sleep leaves you with fewer growth hormones, perhaps stifling your growth and development. If you want to give your growth plates the best chance possible, get lots of rest.