When you think of someone who suffers from acne, we bet something like a vivid "before" photo from a Proactiv commercial pops into your head. The occasional zit isn't considered acne, right? According to cosmetic dermatologist Dr. Kimberly Jerdan, even one or two pop-ups of these unwanted puss-filled visitors is considered acne. Read on to find out what causes random breakouts, plus a few tips on preventing acne.

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You may be wondering how you missed the acne train as a teenager but it's somehow caught up to you as an adult. "One of the most common misconceptions is that acne only affects adolescents," shares Jerdan. "It is very common for a woman or man who never had acne to have some new breakouts with hormonal changes or changes with age."

While there are many causes of acne floating around the internet, from diet to sleeping with makeup on to sweat, there are three main factors Jerdan looks for in patients with acne concerns. The first is whether the patient shows signs of hyperandrogenism, which is excessive levels of male sex hormones (such as testosterone) in the female body due to either hormonal changes or medicines.

Another common cause of acne is called acne cosmetica. This type of breakout stems from occluding makeup or creams, like coconut oil, that clog pores. To ensure you don't suffer from this type of breakout, look for cosmetics with labels highlighting "non-comedogenic" or "non-occlusive" properties.

The third main culprit of acne stems from activities that cause friction and obstruct hair follicles and sebaceous glands. "This type of acne can be caused by dirty cell phones that touch your cheek and chin or athletes who wear helmets regularly that touch their face," says Jerdan.

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The good news is, no matter what causes your blemish, the same few rules apply when treating your zit. "Whether it's a breakout cluster or only one blemish, it's important that you don't squeeze or pop the infected area," warns Jerdan. "Squeezing and popping the pimples can cause hyperpigmentation and scarring." Resist the urge and apply your favorite blemish treatment morning and evening to reduce inflammation and get rid of the acne-causing bacteria.

Try: MD Complete Skin Clearing Breakout Spot Treatment, $27.99