Stress, food sensitivities, your period and other hormonal factors aren’t the only reasons you might be breaking out. And while it may seem that your acne just showed up randomly one day and started causing trouble, there may actually be a link between your everyday habits and sudden or persistent pimples. We spoke with dermatologist Dr. Alan Parks, founder of DermWarehouse, to get his expert insight into some of the surprising, but common, adult acne causes.

Using the Wrong Product for Your Skin Type

“If you start breaking out after using a new product, it may not be the right one for your skin type. Check with your dermatologist about finding an alternative and make sure you ask him or her how to identify what your skin type is. Just because something works well for your best friend, doesn’t mean it will work well for you if her skin type is different than yours.”

Not Washing Your Face After Working Out

“If you’re letting sweat sit on your face after you work out, it’s likely that this will lead to breakouts. Make sure to clean your face ASAP after you exercise, even if you can’t shower right away. Throw the PCA Skin Blemish Control Bar in your workout bag. This product is uniquely packaged in a jar to prevent cross-contamination and is super easy to take to the gym.”

[ Adult Acne: Why You’re Still Breaking Out in Your 20s and 30s ]

Wearing Your Hair in Your Face

“When your hair is constantly falling in your face, the grease and sweat that accumulates in your hair is making its way to your face as well, which can very easily cause acne. If you’re sweating a lot or even if you haven’t washed your hair in a few days, it’s best to pull it back to keep that grease and sweat away from your face.”

Not Washing Your Pillowcase Frequently

“Every night when you go to sleep, the bacteria from your face is transferred to your pillowcase. This happens night after night and can certainly cause you to break out. If you’re washing your face thoroughly before bed, that will surely help, but nothing will do the trick better than washing your pillowcase on a regular basis.”

Forgetting to Moisturize

“It’s true that oily skin is more prone to breakouts, however, contrary to what many people believe, those with dry skin can suffer from acne as well. Acne is caused when your pores become clogged. Usually, this is from oil, but it can also be from dirt, bacteria or dead skin cells. Many acne products also tend to dry out your skin, so keeping it moisturized is extremely important if you’re using any kind of acne treatments.”

Not Cleaning Your Makeup Brushes

“Using makeup brushes that aren’t cleaned regularly is a very common cause of acne. These brushes collect dirt, bacteria, old makeup, oil and more and if you don’t clean them regularly, you’re just putting all of that right back onto your face each morning. Dirt, bacteria and oil are a recipe for disaster when it comes to your skin, so make sure to keep those makeup brushes clean!”

Talking on Your Cell

“These days, we’re on our cell phones 24/7. We touch them with dirty hands and then put them up against our faces when we’re chatting away. This transfers any dirt and bacteria that has accumulated on your phone right onto your face, which can lead to breakouts and acne. Make sure you are cleaning your phone on a regular basis. Not only will this keep you from getting sick and make you healthier all around, it will also help with breakouts.”

[ Next: Face Mapping Your Acne: What Your Breakouts May Be Telling You ]