It's Acne Awareness Month, and we know the only thing more frustrating than recurring breakouts is not knowing where they come from. That's why we're getting to the bottom of the problem. Is it stress? Hormones? Or just terribly bad complexion luck? Worry no more. Instead, clear up your mind — and your skin — with this guide to the causes of breakouts. Once you know what's causing acne to flare up, it's easy to develop a plan of attack. Read on to see what culprits could be responsible for your blemishes (and what to do about it).
Your Makeup Brushes Aren't Clean
On your list of things to do, washing makeup brushes probably ranks somewhere between watching an ALF marathon and cleaning the litter box. If you want a clear complexion, though, you've got to do it. Otherwise, bacteria grows — and dirty brushes will just transfer that bacteria to your face.
>> Learn how to clean your brushes 
It's in Your Genes
Did your dad have acne? Do your siblings? Lucky you, it just might run in the family. A 2002 British study suggests that 81 percent of acne can be attributed to genetic factors rather than environmental ones. File this one under "not your fault."
You Work Out
Sweat itself doesn't cause breakouts, but it can mix with oils in your pores — and that can lead to acne. Friction can also aggravate acne, so wear loose-fitting clothing made of natural fabrics; synthetic fabrics such as Lycra and nylon can rub against skin, trap sweat, and clog pores. When showering after a workout, use a body wash with salicylic acid to keep pores clean.
>> What to pack in a gym bag 
It's That Time of the Month
Hormones called androgens overstimulate the skin's oil glands, which frequently leads to a breakout around menstruation. (If you break out along your jawline, this is the likely culprit.) Some women find relief by going on oral contraceptives — aka the Pill — but you'll need to discuss the benefits and risks with your doctor.
You're Picking at Your Face
You know that whitehead that's just begging to be popped? Leave it alone. Same with blackheads, nodules, and everything else. Picking at your skin introduces more germs, increases the chances of scarring, and can increase inflammation — which means more breakouts.
You're Allergic to Laundry Detergent
Especially for people with sensitive skin, laundry detergent and dryer sheets can irritate the skin. Some people even develop contact dermatitis and mistake it for acne. Swap your usual soap for fragrance-free detergent, skip the dryer sheets, and this could clear things up.
It's the Weather
First things first: that idea that a little sunshine helps acne? It's a myth. But weather changes can affect your skin. Changing climates and seasonal shifts might be the cause of your breakout. If you've recently moved or have taken a vacation, see an aesthetician or dermatologist. Usually they'll be able to help your skin get back to normal.
You Need More Sleep
Ever think your acne is getting worse overnight? It could be. Not sleeping enough inflicts stress on the body, which raises levels of cortisol, the so-called "stress hormone." In turn, cortisol creates breakouts. Aim for eight hours of sleep per night, even if you have to wear a sleep mask or earplugs to catch those z's.
>> The five worst sleep mistakes 
For some women, a baby on the way means acne in the here and now. Progesterone increases during pregnancy, which can affect the skin's oil levels. While several safe treatment options exist, others such as Accutane and tetracycline can cause birth defects. To be safe, talk with your obstetrician before embarking on a new skin care routine.
>> What's safe (and not) for pregnant women 
Along with lousy peanuts and security lines, frequent fliers have one more thing to look forward to: acne. The air in planes is very dry, which can trick your skin into producing even more oil. If you have to be up  in the air, pack a noncomedogenic moisturizer in your carry-on.
>> How to look better after a flight 
You're on Drugs!
OK, we're talking prescriptions here, but it's worth looking at your Rx. Is acne listed as a side effect? Well, there you go.
You're a Bundle of Nerves
Ever notice how your skin seems to break out right before a big event like a job interview? It's not a coincidence. Simply put, stress is terrible for your body — and that includes your skin. Stress raises levels of cortisol, which increases inflammation and causes oil glands to go into overdrive. While completely avoiding stress is impossible, you can improve your skin (and overall well-being) by meditating, relaxing, spending time with animals, or doing anything else that calms you.
>> Why helping others lowers stress 
Those Sheets Are Dirty
Not to sound like your mom, but . . . when was the last time you changed your sheets? Bed linens can harbor bacteria, which are more than happy to multiply on your face. Change your pillowcases at least twice a week. That goes for towels, too.
You're a Chatty Cathy
Breaking out on your cheeks? Your phone could be the culprit. Pressing a phone to your skin can lead to a breakout. Once a week, clean your phone with an alcohol wipe — and if you've been on the phone for more than 15 minutes, it might not be a bad idea to cleanse your face, too.
Your Diet Is Breaking You Out
Want to change your skin? Change your diet. Eliminating dairy, caffeine, peanuts, seaweed, sugar, and soy can lead to clearer skin. Swap almond milk for cow milk, bid adieu to brie, and choose water over soda. Good-for-your-skin foods include salmon, dark leafy greens like kale, and antioxidant-rich green tea. Give it a month and see what happens. After all, you are what you eat.
>> The best (and worst) foods for your skin 
Products Are Clogging Your Pores
Comedogenic ingredients build up in pores, and unfortunately, they're in plenty of beauty products. Looking for products with "noncomedogenic" labels is a good place to start, but because there's no regulated standard, you'll need to compare a product's ingredients to the comedogenic list .
You're Washing Too Much — Or Not Enough
Cleansing your face of sebum, makeup, and dirt is important. Some acne sufferers, however, believe that washing more frequently will lead to better skin. Not so! Cleansing in the morning and evening is all that's necessary. Any more than that, and you could irritate or dry out your skin.
It's Your Toothpaste
If you break out around the corners of your mouth, your toothpaste is the likely culprit. Aesthetician Kimberly Yap Tan of Skin Salvation  recommends Kiss My Face's all-natural variety to her clients. And that old tip about using toothpaste to heal a pimple? It's a myth.
You Go to Bed With Makeup On
We know, we know — you're tired. But hitting the hay without washing your face is a surefire way to trigger a breakout. If you're too exhausted to do a full skin care routine, get the worst of it off with a cleansing wipe.
You're Not Using Effective Treatments
Unfortunately, cleansing your face isn't enough to make acne flee. To battle pimples, you'll need ammunition in the form of over-the-counter or prescription treatments. Benzoyl peroxide kills the bacteria that causes acne, so it's highly effective as a preventative measure. Likewise, salicylic acid can keep pores from clogging.
When that's not enough, a dermatologist can offer help. Oral and topical antibiotics, topical retinoid creams, and chemical peels can all make a difference.
You're Not Giving It Enough Time
Are you all "hurry up please it's time" with your complexion? Slow down, little jaguar. Miracles don't happen overnight, so if you expect your skin to clear up in days, you'll be disappointed. Depending on your age, it may take up to three months for your skin cells to turn over and reveal new skin. Be consistent with your skin care regimen, and be patient.