If you have persistent acne, it might be worth it to get some blood work done as a way of seeing what's going on internally. As Kristina Goldenberg, of Goldenberg Dermatology in NYC tells Bustle, " A good skin care routine may not be enough to control acne if a woman’s hormone levels are out of norm. Evaluating levels of different hormones can help determine the cause."

Blood work might also reveal an underlying condition that's contributing to your acne, such as polycystic ovarian syndrome. "Conditions such as polycystic ovarian syndrome, hidradenitis suppurativa [a skin condition that can cause small lumps under the skin], or an overproducing pituitary gland can be the cause of acne that defies conventional treatment," Dr. Franziska Ringpfeil, of Ringpfeil Advanced Dermatology, tells Bustle. If that ends up being the case, your doctor can prescribe treatments to even out your hormones, and reduce your acne.

What you have for breakfast each morning can play a role, too. So if you eat or drink the same thing every single day, it may help to think about the effect it's having on your body.

Take protein shakes for example. "It’s important to remember that many protein shakes have trace amount of steroids that may cause breakouts. That may be another reason for persistent breakouts," Goldenberg says. "Unfortunately it's trace amounts, so it's often not listed or mentioned in the labels. So I often just tell my patients to stop all protein shakes if the acne is persistent." By making a few lifestyle changes, and going for foods and drinks that are more organic, you might notice a big difference.

When was the last time you washed your makeup brushes? "If you aren’t cleaning your makeup brushes, they could harbor bacteria that cause you to break out," says Farber. To help prevent all those germs from ending up on your face, aim to wash concealer and foundation brushes at least once a week, and you should see an improvement in your skin.

If you're someone who wears makeup everyday, it may be worth it to update your brands — especially if your acne is persistent. "Non-mineral makeups may contain a long list of ingredients with harsh chemicals, dyes, fragrance, and preservatives. These ingredients are known irritants for many people," RealSelf contributor Dr. Joel Schlessinger, tells Bustle. "Non-mineral formulas are often liquid, and far more likely to soak into the skin, clogging pores, and exacerbating acne. They also usually contain oil, which can cause a disruption in the skin’s natural balance."

Many people see an improvement in their skin after switching to mineral makeup. "Made from natural minerals that are mined from the earth, mineral makeup is designed to remain on the skin’s surface, creating a natural barrier against environmental factors," Schlessinger says. "Because it stays on top of the skin, mineral makeup won’t clog pores, making it a great option for those who are prone to acne."

If you're like most people, you probably spend a good portion of the day with your phone pressed up against your cheek. And if you're prone to acne, this habit will only exacerbate the oil on your skin.

"It’s no secret how dirty our smartphones can be," Schlessinger says. "Microbiologists estimate that the average phone could have more than 25,000 germs and bacteria per square inch ... We’re always touching doorknobs, money, and other germ-covered objects and then touching our phones. Then when you touch your phone to your cheek, all those bacteria work their way into pores, leading to acne and inflammation." To reduce the amount of phone-to-skin contact you've got going on, try using a headset or your headphones when making calls. You can also use an antibacterial wipe to give your phone a once over, before touching it to your face.

While you might think a complex skincare routine is your ticket to clear skin, the opposite is often true. "More is not always a good thing," says Farber. "Too many products can irritate and dry out your skin, so glopping your medications on your pimples is not going to be helpful." Using acne medication sparingly, or as directed by your dermatologist, is key.

And same goes for your cleansers. "Other contributing factors as to why your acne may be coming back or sticking around are ... overuse of certain soaps, exfoliants, and detergents, as washing is removing surface oil — not the sebum in the follicle where the issue is," Dr. Mirela Mitan, PhD, founder and CEO of MMXV Infinitude Skincare, tells Bustle. "As a result, this is actually worsening the acne. Over exfoliating removes the skins natural barrier, so especially if your skin is sensitive, only exfoliate once per week."

If you use products on your hair, be careful about spraying them onto your skin, or letting the product seep onto your face. "Thick hair care products like pomades can physically block pores leading to breakouts," Joshua Zeichner, MD, director of Cosmetic & Clinical Research in Dermatology at Mount Sinai Hospital, tells Bustle. "This may be especially prominent around your hairline and forehead." If you have acne in these areas, it may also help to wash your face after doing your hair.

Again, not all causes of acne are external. As Zeichner says, pesky acne can sometimes be due to internal inflammation. So it may help to avoid certain foods that increase inflammation in the body — like sugars and starches — while eating more foods that reduce inflammation, such as green leafy vegetables, nuts, blueberries, and oranges. In doing so, you might see a big difference in your skin.

If you have an allergy to something in your diet, it may show up on your face in the form of inflammation and pimples. "If acne is continually persistent and it seems product changes are not making an impact, it’s time to look inside," Heather Wilson, licensed esthetician and director of Brand Development at InstaNatural, tells Bustle. "If you feel you may be facing an intolerance, allergy, or hormone imbalance, seek feedback from your physician or dermatologist and be sure to express your skin concerns and troubles." They can check you for acne-causing issues, such as lactose intolerance, and tell you where to go from there.

Think about your day-to-day life, and all the germ-y things that might be coming in contact with your skin, and thus blocking your pores.

"When dealing with acne, it is essential to first figure out if there are any obstruction causes," Dr. Robert Morrell, MD, founder and director of Medical Rejuvenation Center and Di Morelli Skin Care, tells Bustle. "Preventing an obstruction cause can prevent the clogging of your pores. Obstruction causes can be anything mechanical such as subconsciously putting your hands on your cheeks while you’re at your desk for long periods of time, wearing a headband over your forehead while you exercise, or even just not using a clean pillowcase." By removing these factors from your life — not touching your skin, washing your pillowcase more often, etc. — you can reduce your chances of acne flareups.

Even the world's most ideal skincare routine is often no match for stress. As Morrell says, "Stress is an obvious but often overlooked reason for recurrent acne. If you can’t make sense of any reason that could be causing your acne, be more aware of your mental state and see if you’re more stressed than usual." By reducing your stress — perhaps by meditating every day, doing yoga more often, or taking walks when you're feeling overwhelmed — you'll likely be rewarded with clearer skin.

Because when it comes to fighting acne, there's often much more to take into consideration than just your face wash and zit cream. By paying attention to and treating outside factors (like dirty makeup brushes) to internal factors (like hormonal imbalances) you can definitely clear up your skin.