Your 20s are full of new jobs and dates and trips and parties and mistakes that you can fix (or forget about) in your 30s. And there's basically no time for sleep.
Unfortunately, late nights don't just make morning suck. When you keep not getting enough sleep, it can affect your body in the long run. (The American Academy of Sleep Medicine [AASM] recommends between 7 and 9 hours of sleep per night for adults.
Experts are just beginning to understand how sleep affects just about everything you do. But they do suggest you look out for these scary side effects of skimping on sleep in your 20s:
1. Increased risk of disease:
In a recent study involving more than 54,000 adults, researchers found that people who sleep less than six hours per night (or more than nine) were significantly more likely to have heart disease or diabetes, have suffered a stroke, or be obese, even after researchers adjusted the results for other known risk factors.
2. Heightened blood pressure:
Sleep loss stresses out your body and mind in a way that causes your blood pressure to spike. Over time, this could damage your heart, arteries, kidneys, and even bring about stroke, loss of vision, and a host of other health problems you seriously don't want.
3. Weakened immune system and reduced effectiveness of certain vaccinations:
Vaccines are designed to trick your body into creating antibodies that provide immunity to a particular disease or infection. But exhaustion compromises the immune system, so your body doesn't produce adequate antibodies, according to a study in which researchers administered hepatitis B vaccinations and measured patients' antibodies before and after treatment. People who slept fewer than six hours a night were the least likely to respond to the vaccine and were 11.5 percent more likely to emerge unprotected.
When you don't get enough sleep, your body naturally releases the stress hormone cortisol, says Dr. Shalini Paruthi, director of the Pediatric Sleep and Research Center at SSM Cardinal Glennon Children's Medical Center in St. Louis, Missouri, and an AASM fellow. And it doesn't matter whether you were up late to work on spreadsheets or to work on catching up on Scandal.
5. Greater risk of death:
People who sleep less than five hours per night are 15 percent more likely to die from literally any cause, according to data from three massive studies. So yes, going to bed too late could eventually kill you.
6. Impaired creativity:
Neuroimaging studies suggest that the brain spontaneously reorganizes information when you rest, which could explain why it's so much harder to focus and come up with ideas when you haven't slept.
There's something about exhaustion that turns you into Negative Nancy: In a two-year study in which 78 medical residents tracked their sleep and intermittently recorded their emotional responses to various stimuli, researchers found that fatigue intensified participants' negative emotions. Sleep deprivation actually affects your mood even more than it does your motor and cognitive performance, according to a massive review of 19 original research studies published in Sleep. Meaning? You're more susceptible to angry tangents when you're sleepy.
8. Lower grades:
Research suggests that college students who sleep the least earn lower grades than those who sleep nine or more hours per night. Your brain needs to cycle through certain deep sleep stages to store memories and solidify the things you learn. When you fall asleep, your heart rate and metabolic rate drop so your body can focus on those things, says Dr. Paruthi. No sleep, no storage.
9. Poor decisions:
Many parts of the brain are involved in decision-making. When you don't give your brain enough rest, it functions at half-mast, and you'll end up making less than savory choices, Dr. Paruthi says.
10. Twitchy eyes:
Dr. Paruthi says fatigue can cause an awkward-looking eye spaz called nystagmus, which makes your eyeballs move even involuntarily, even though your head is still.
11. Fertility issues:
While there's no conclusive proof that sleep deprivation directly causes infertility, experts know that lack of sleep can stress you out and suspect it can also can interfere with your body's circadian rhythm. Together, this can ultimately suppress your reproductive hormones and impair your ability to sustain a pregnancy, according to an article published in Sleep Medicine.
12. Sex drought:
Sleep or sex? Sex or sleep? When you're really, really tired, you don't always get to chooZzZz.
13. Weight gain:
Countless studies have found that people who sleep less are more likely to be overweight. That's probably because sleep deprivation messes with the hormones that regulate your appetite (ghrelin) and tell your brain you're full (leptin), which can lead to chronic overeating, according to a review of experimental and observational studies of sleep published in The American Journal of Human Biology.
14. Fat Gene activation:
Sleep loss basically turns your body against you: Research done on twins suggests that skimping on sleep (i.e., sleeping less than seven hours per night for the purposes of this study) fires up whatever fat-storing genes you have to increase your risk of gaining fat and holding on to it for good.
15. Emotional eating:
In a recent study of 114 college students, participants were more likely to increase their food intake in response to strong feelings when they were particularly tired.
Sleep and depression are interrelated: Research suggests people who suffer from insomnia are more likely to suffer from major depression than people who sleep regularly.
17. Increased risk of car accidents:
"Sleep-deprived patients in simulators have just as many accidents as someone who is drunk," Dr. Paruthi says.
18. Slower reaction time:
When your brain isn't well rested, it doesn't take in information, process it, and respond to it as quickly as usual. "You lose speed before accuracy," Dr. Paruthi explains. "You'll get your work done, but it will take longer."
19. Tired partner:
Even if you're the lone wolf who stays up late to online shop or binge-watch your favorite shows, you're not the only one who suffers sleep debt and associated side effects. If you sleep with a partner, you'll likely wake him up when you jump into bed a few hours later, which compromises his sleep quantity and quality. Regular rude awakenings could cause him to experience any number of the side effects listed here.
Shaking can mess with your ability to carry out precise movements and detail-oriented tasks, like needle threading and tweezing your eyebrows. Which you really don't want to mess up.
21. Premature aging:
When you don't get enough sleep, your body releases the stress hormone cortisol. If your body releases too much cortisol, it starts to break down collagen, a protein that promotes smooth skin and elasticity. Sleep deprivation also may decrease the production of the growth hormones in your body that strengthen the skin and fend off wrinkles, says Dr. David Bank, dermatologist and director of The Center for Dermatology, Cosmetic, and Laser Surgery in Mount Kisco, NY, and author of Beautiful Skin – Every Woman's Guide to Looking Her Best at Any Age. Skimp on sleep and you'll lose the restorative effects that make your skin look young and healthy.
22. Dry skin:
Sleep helps hydrate your skin so it doesn't get all dry and flaky. In other words, adequate sleep is like a natural moisturizer.
23. Big-time breakouts:
When you don't get enough sleep, your stress levels soar and your body responds by producing more of the hormone glucocorticoid. This disrupts your skin structure, which makes you more vulnerable to acne. Lack of sleep also triggers inflammation, which can makes small blemishes blow up.
24. Dull skin:
Sleep improves blood flow to the skin, Dr. Bank says. Don't get enough sleep, and your skin will look blotchy or pale.
25. Skin sensitivity:
Your body's immune system builds its strength while you sleep, Dr. Bank explains. Sleep deprivation can make your skin more sensitive and even worsen existing skin conditions like rosacea or eczema.
Do You Get Enough Sleep?
If you get into bed and fall asleep within 20 minutes, don't remember waking up throughout the night, and wake up feeling refreshed each morning, you should be good to go, Dr. Paruthi says. If not? The best way to find out how much sleep you need is to go to sleep when you feel tired and wake up without an alarm for a few days at time—like when you're on vacation. Then set a bedtime and stick to it for all of the reasons above.
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.