1. You forget/are too lazy to wash your face before you go to sleep.
Just because you're exhausted doesn't mean you get a free pass. "Neglecting to cleanse your skin leads to a buildup of oil and dirt, which ultimately causes breakouts and even bacterial infections," says Elena Arboleda, head aesthetician at Mario Badescu Skin Clinic in NYC. Perpetual breakouts into your 30s—who wants that? And you'll have to deal with the acne scarring to boot. Keep a packet of face wipes by your bed, so that even in a lazy emergency, you can clean off your makeup. You can also douse a cotton ball with a gentle cleanser like micellar water that doesn't need to be rinsed off.
2. You pull all-nighters or don't get enough sleep.
Skin repairs itself while you sleep, so not getting at least eight hours can lead to a sallow, dull complexion. That alone will make you look much older than you are, not to mention the dark circles that'll come with it.
3. You drink too much coffee to make up for the sleep you didn't get.
The caffeine in coffee is dehydrating and if you drink too many cups a day too often, your skin will go from plump and dewy to dry and dull. Plus, any fine lines you may start to see will begin to look more pronounced. Quench thirsty skin with a super-hydrating serum, which immediately replenishes moisture loss, thanks to hydrating katafray extract. Hydrate your skin to have nice skin forever.
4. You party too much (aka have one too many too often).
It's fun to sip on a cocktail here and there, but drinking too much on a regular basis is not only unhealthy for you internally but it can also dehydrate your skin. If having a drink is your vice, make sure to have a glass of water for every alcoholic beverage you consume to keep your hydration levels high. Bonus: Going one for one also helps prevent hangovers. To replenish any lost moisture in your skin immediately, use a serum with hyaluronic acid, which holds 1,000 times its weight in hydration and draws moisture from the air into your skin.
5. You experiment with recreational drugs.
Drugs aren't good for you health-wise, which you already know, but one of the ways they can manifest is on your skin. Bottom line: Don't do them and you'll look younger longer.
6. You smoke when you drink.
OK, even if you aren't the one bumming a cigarette when you're tipsy, secondhand smoke can still trigger premature aging to occur, which causes the collagen and elastin to break down, leaving your skin saggy.
7. You're stressed.
Attribute it to guys, school, work—whatever the cause, stress can wreak havoc on in the short and long term. It can bring about blemishes, cause dullness and rashes, and even cause you to furrow your brow over and over, etching lines in your face that will stick with you for life. To avoid stress, take a break from your busy schedule and do something fun with your girlfriends.
8. You aren't exercising on a regular basis.
I hate to break it to you, but your body isn't going to look that bangin' forever. Which is why it's a good idea to keep yourself in shape now, so you don't have to work out so hard later on in life to stay healthy. Plus, exercising not only gives your skin a gorgeous glow immediately, it also helps keep stress levels down (Bye, stress-related breakouts!), helps shed dead skin cells, and boosts your mood.
9. You skip meals.
Imagine this: You're running all over the place and haven't had a second to down some lunch. At that point, your brain is not only running on empty, but constantly missing meals can cause your skin to age faster and dry out more quickly. To make sure your operating on all cylinders, pack healthy snacks, like peanuts or almonds— even an orange (which has skin-brightening vitamin C)—and stash them in your bag. That way, you won't go hungry during the day and you can keep your skin healthy at the same time.
10. You don't drink enough water.
Regardless of your schedule, if you don't guzzle eight glasses or more a day, your body won't get the right amount of hydration you need internally, which can show up as dry, flaky patches on your skin. Make water taste yummier by slipping fruit slices into a pitcher of water, keeping it in your refrigerator, and then filling up your water bottle before heading out the door. Also, to make sure your skin stays supple and hydrated throughout the day, toss a hydrating face mist into your bag.
11. You constantly touch or pick at your skin.
Whether you're simply leaning your face on your hand or picking dry skin from a healing blemish, you're transferring bacteria from your fingertips or palms onto your face. This can trigger new breakouts, exacerbate existing acne, or even cause scarring, which will leave your skin dotted and uneven, Arboleda says.
12. You pop your pimples.
I get it, sometimes you can't walk out of the house with a whitehead staring back at you, but if your trouble spot doesn't look like it's ready to pop on its own, you shouldn't force it. By attempting to pop your own zits, you can actually cause pores to enlarge.
13. You eat too much sugar.
Everyone has a sweet tooth, but consuming too much candy can cause glycation, which is when excess sugar breaks down collagen (which gives your skin its structure) and causes sagging over time. Need a treat? Turn to something healthier, like organic dried fruit or a piece of dark chocolate.
14. You share makeup with your roommate or friends.
Just because you're getting ready with your BFF in your apartment doesn't mean that gives her a free pass to use your mascara. When you share makeup, you run the risk of getting a skin or eye infection, cold sores, conjuctivitis ... do I need to go on? It's not rude to say, "Oh, I'm sorry, I don't share my makeup." Remind her in advance to bring her own makeup bag to avoid any awkward convos like this.
15. You wear heavy makeup.
Piling on the makeup doesn't allow your skin to breathe and can clog your pores, resulting in acne. Every few days, go lighter on your application (Tinted moisturizer and mascara will do!) or go au naturel to give your skin a break. Less is more, anyway!
16. You choose your products based on what your friend uses.
Getting recommendations from a well-informed friend is exciting, but what may work for someone else skincare-wise may not work for you. So, as *fun* as it is to think your skin is going to look like Suzie's when you're done, it probably won't. Plus, if you're using the wrong formula for your skin, it could break you out, which is S T R E S S F U L. To make sure you're using the right product for your skin, make an appointment with your derm and haul your products into his or her office to get approval.
17. You talk on your phone nonstop.
Holding your phone against your cheek can lead to breakouts and rashes along your jawline. Make sure to clean your screen daily using an antibacterial wipe!
18. You still go tanning because you like looking like a bronze bombshell.
Sure, a golden complexion is gorgeous, but it's not worth risking your skin and health for. Tanning beds emit the same harmful UV radiation as the sun and cause premature aging and skin cancer, which can leave you battling for your life or worse off, dead. The healthier way to get a glow? Slathering on self-tanner or even getting a spray tan, and when you are at the pool, slather on SPF religiously and wear a hat to help shield your skin.
19. You don't wear sunscreen because you think it breaks you out.
Here's the truth: If you're using the wrong sunscreen, it might clog your pores and brew blemishes. If you're acne-prone, go for oil-free formulas. Otherwise, just make sure the label on your sunscreen says, "noncomedogenic," fragrance-free," "broad spectrum," and is SPF 30 or above. This winning combination will keep your skin clear and protect it from the sun's harsh rays, which breaks down collagen and elastin, causing fine lines and wrinkles, and can also lead to sun spots later on in life if you don't prevent them with SPF early on.
20. You avoid anti-aging products because you think you're too young. You might not think you need to start early when it comes to anti-aging products, but these fountain-of-youth, peptide- and vitamin A-packed products are what will keep you looking thirtysomething when you're actually in your mid-40s. Want just the bare essentials? Gervaise Gerstner, a cosmetic dermatologist in NYC, suggests using 20-percent glycolic pads three nights a week, skipping a day in between, and using a retinol-based product on the nights you haven't swiped your face with the glycolic pads. Remember not to leave your neck, chest, and hands out of the preventative fun.
This article originally appeared on Cosmopolitan.com. Minor edits have been made by the Cosmo.ph editors.