Sleep is magical, and few things are better than a good night’s rest. But what happens when you find yourself not getting enough sleep? Do a few restless nights really matter? You betcha.

Your body uses sleep wisely, taking that precious time to build up your immune system, process information, and reset before a new day begins. When you don’t get an adequate amount of sleep, all these functions and more are thrown off-kilter.

Sleep is essential, and not getting enough on a regular basis will lead to trouble. So, how many hours should you be shooting for? On average, the sweet spot for primo sleep for adults is 7 to 9 hours per night.

Getting less than that could put you in the danger zone. And you wouldn’t be there alone. According to a 2012 study, roughly 1 in 3 American adults are getting too little sleep.

Share on Pinterest
Infographic: Mekhi Baldwin

Sleep deprivation is caused by consistently not getting enough sleep or experiencing lower-quality sleep. A sleep disorder like insomnia can also be the culprit.

Other common sleep disorders:

How can you tell you’re sleep-deprived? Look out for signs like these:

  • fatigue during the day
  • irritability
  • frequent yawning
  • excessive sleepiness

Too many restless nights and you’re in for a bodily rebellion. A lot can happen to your body if you don’t get enough sleep.

1. A weakened immune system

Think of your immune system as an army, always at the ready to protect you against the evil forces of infection and disease.

Just like an army, your immune system needs time to build its defenses. When you’re sleeping, your immune system kicks into gear and prepares itself by building up substances (like antibodies and cytokines) that help fight infection.

Not getting enough sleep weakens your immune system by not allowing it to create sufficient protection. And when your immune system’s defenses are down, your chances of getting sick go up. Lack of sleep also makes recovery longer when you do get sick.

2. Respiratory issues

Your respiratory system relies on quality sleep to keep itself strong, and vice versa. But some diseases and disorders get in the way of this symbiotic relationship.

Obstructive sleep apnea (OSA) is a nighttime breathing disorder that can impact the quality of your sleep by disrupting your peaceful Zzz’s. Consistently waking up throughout the night due to OSA can lead to sleep deprivation.

Sleep deprivation can also make you more susceptible to respiratory infections like the flu or the common cold, as well as worsen existing respiratory illnesses.

3. Heart problems

When it comes to matters of the heart, either too little or too much sleep can have a negative effect on your cardiovascular health. Getting less than 5 hours or more than 9 hours of sleep each night has been linked to an increased risk of heart disease, stroke, and heart attacks.

4. Increased cancer risk

A 2015 study found that lack of sleep is linked to increased risk of some cancers, including prostate cancer, breast cancer, and oral cancer. Falling asleep and staying asleep can be difficult for people who are undergoing cancer treatment and can be a lasting challenge long after remission.

There’s also a risk for those who work overnight shifts. Several years of overnight light exposure may reduce your body’s levels of melatonin, a hormone that helps you sleep. This can encourage cancer growth. Getting at least 7 hours of sleep each night can help you stay healthy.

5. Increased diabetes risk

Lack of sleep also prevents your body from releasing enough insulin, a hormone that lowers blood sugar levels. This can cause your blood sugar levels to spike, which can increase your risk of developing type 2 diabetes.

In a 2015 review of studies, researchers concluded that 7 to 8 hours of sleep is ideal for keeping your insulin at a healthy level.

6. Trouble thinking

As the hit ’90s movie adaptation of The Baby-Sitters Club books reminds us, the brain is the center of the chain. But if you don’t get enough sleep, your mind can become cloudy, which can lead to all sorts of issues.

Memory, problem-solving skills, and even creativity can be negatively affected by just one night of missed sleep. In a small 2011 study, 18 men completed two tasks: one after a full night’s sleep and one after a night of no sleep. Not surprisingly, the night of no sleep had negative effects on alertness, reasoning, and reaction times, among other factors.

7. Forgetfulness

Difficulty remembering things goes hand in hand with trouble thinking. As it turns out, sleep has a huge impact on your memory and ability to learn.

Sleep helps your brain “lock in” information, allowing you to store it and retrieve it when you need it. Sleep keeps you sharp and ready for that next (likely virtual) trivia night!

8. Little to no sex drive

Yep, you read that right. When you don’t get enough sleep, you don’t want to get it on.

A small 2011 study found that lack of sleep lowered levels of the sex hormone testosterone in healthy young men by 10 to 15 percent. Participants also experienced changes in their overall mood as sleep levels decreased. Talk about a mood killer!

And according to a 2015 study, getting enough sleep is also important for sexual desire in women. The study found that women who got more sleep were more interested in sex the next day. Women who slept longer on average also felt more aroused than those who slept for shorter periods.

9. Weight gain

While it’s normal to enjoy the occasional late-night snack, sleep deprivation can cause nighttime munchies to become a regular occurrence.

A lack of sleep impacts your brain’s production of the hormones that control hunger and fullness. Not getting enough sleep triggers a decrease in your level of leptin (the hormone that tells your brain you’re full) and an increase in ghrelin (which boosts your appetite), leading to pre-bedtime snacking.

Lack of sleep is also connected to insulin resistance, which can decrease your body’s tolerance for glucose (aka sugars).

A 2012 study looked into the connection between weight and sleep in 21,469 adults over a 3-year period and found that those who got less than 5 hours of sleep per night had a higher chance of weight gain and eventual obesity.

10. Increased risk of accidents

Getting behind the wheel when you’re operating on minimal sleep can lead to disaster. According to a 2018 study, people who get 6 hours or less of sleep each night have a greater risk of getting into a car accident than those who sleep 7 to 10 hours. And the risk increases with each hour of sleep lost. Yikes!

This can especially impact you if you work long hours, if you’re a shift worker or a commercial driver, or if you travel often.

A lack of sleep can also affect your balance and coordination, making you more likely to fall, bump into things, or have similar physical accidents.

11. Skin issues

They don’t call it “beauty sleep” for nothing. Not getting enough sleep will wreak havoc on your skin.

A small 2015 study funded by the Estee Lauder Companies found that women who didn’t get enough good-quality sleep had more significant signs of skin aging and decreased skin barrier function. More research is still needed to fully understand how sleep affects the skin.

12. Disrupted hormone production

Sleep has a huge impact on your body’s hormone production, and not getting enough can throw your hormones out of whack. For instance, adequate testosterone production requires at least 3 hours of high quality sleep.

Lack of sleep can also mess with the growth hormones that affect your height and overall growth. Growth hormones are important to help repair your tissues and cells and to build muscle mass. Getting too few Zzz’s can alter this hormone production.

13. Mood changes

You know that cranky feeling after a restless night? That’s thanks to not getting enough sleep!

Too little sleep can take a toll on your mental and emotional state, making you more susceptible to mood swings and paranoia. When left untreated, sleep deprivation can even cause you to see or hear things that aren’t actually there (aka hallucinations).

In people with certain mental health conditions, not getting enough sleep may lead to an increase in certain symptoms or behaviors.

It’s a no-brainer that the best remedy for a lack of sleep is to ensure you’re getting plenty each night (7 to 9 hours!). It’s also important to make sure you’re getting enough quality sleep.

Try these tips to get your sleep cycle back on track:

  • Go to bed and wake up at the same time every day (yes, even on weekends and holidays!).
  • Avoid snacking or eating meals too close to bedtime.
  • Limit or avoid napping during the day (we know, this one sucks).
  • Exercise regularly (but not too close to bedtime!).
  • Keep your alcohol intake low.
  • Don’t consume caffeine after noon.
  • Avoid using electronics before bed (put the phone down).
  • Create a pre-bedtime relaxation ritual (like meditation or a hot bath).

Sleep schedule still off? If you’re still having issues sleeping or you’re experiencing chronic fatigue during the day, it’s time to talk to your healthcare provider. They can work with you to get to the root of the problem and find a course of treatment to help you get some shut-eye.