Zits, whiteheads, blackheads, papules, pustules—acne stinks, and it affects a large number of people.

In fact, according to the American Academy of Dermatology, more than 40 percent of adolescents have acne or acne scarring by the time they’re in the middle of their teen years.

Changing hormones, emotional stress and dead skin cells clogging up the pores are the main causes of acne breakouts, according to esthetician Nicole Thompson.

"When it comes to moisturizers, don’t think ‘my skin’s oily I don’t need one,’" Thompson said. "What happens is that the oil over-produces itself, so it causes excess oil. You need to use a moisturizer that is oil-free so it’s not going to make your skin have more oil."

For oily skin, it’s important to find a cleanser that is oil-free.

"They’ll say ‘help to tighten up the pores’ or ‘remove excess oil,’" Thompson says.

She also explains that great words to look for are "non-acnegenic" and "non-comedogenic," meaning that they are not going to cause acne and they will not irritate existing acne.

Oily skin needs moisture because the skin needs a balance of oil and water.

"The skin produces oil, not water," Thompson said.

"If the oily skin feels dehydrated, it will protect itself by producing more oil, so need moisturizers, even though your skin is oily."

For dry skin that appears to be acne-prone, it’s likely that the cause is dead skin cells on the face. These skin cells clog pores. Using exfoliants, chemical or manual, can help dryness.

There is no certain cure for acne—but it can be controlled. Dermatologists may recommend treatments such as Aczone, Retinae, Epiduo or even oral medication like Minocycline. There are also over-the-counter, three-step systems like Proactiv.

Thompson recommends using derma peels, which are cosmetic treatments containing exfoliant crystals to remove dead skin cells which helps prevent acne and scarring caused by acne.

The secret to a clear complexion, according to proavtiv.com, is treating the whole face to prevent breakouts before they start. It’s impossible, however, to pinpoint one specific skincare routine that will work for everyone.

When planning a skin care routine for acne-prone skin, one should pay close attention to the active ingredients in the products; ones with benzoyl peroxide or salicylic acid work best.

"Salicylic acid is going to be less harsh. It’s going to go down and clear out the skin," Thompson said.

According to dermnetnz.org, salicylic acid works by softening keratin, a protein that forms part of the skin structure. This allows dry, scaly skin to be removed easier so, when paired with other medicines, it takes off the upper layer of skin allowing the additional medicines to penetrate more effectively to clean pores.

"You need to wash your face morning and night: cleanse, tone and moisturize," Thompson said.

"Start by splashing your face with warm water," she explains, "and then just do a light circular motion with a cleanser on a cleansing brush or on your fingers."

Toners take off the extra residue that the cleanser leaves behind and they also help tighten pores.

"Some (toners) even do light exfoliation with the alpha-hydroxies in them," Thompson added.

Next use a spot treatment that contains an ingredient like salicylic acid, followed by daily, leave-on exfoliants.

"(Exfoliants) are non-abrasive and those will go down and get rid of the dead skin cells daily for you," Thompson said. "Follow with a moisturizer."

Thompson recommends a faithful routine. "Once you do something for two weeks, it helps become a habit. You didn’t get acne overnight, so it’s not going to go away overnight."

People who wear makeup must be aware that when choosing a foundation and other cosmetics, there are some things to consider to prevent skin irritation.

According to teens.webmd.com, searching the label of each product is key to getting a polished look while avoiding acne.

Terms like "non-oily" and "hypoallergenic" mean that a product won’t cause an allergic reaction. "Non-comedogenic" means that a foundation won’t clog pores.

"The main thing is the oil-free and making sure that your pores aren’t going to be clogged so a lot of times they’ll say ‘non-cakey’ or ‘non-clogging,’" Thompson says.

"And, don’t go to bed with your makeup on because, of course, it’s going to sit there and clog up the pores," she advised.

Picking at breakouts will not only push the dirt and impurities deeper into the skin, but also cause scarring, according to Thomson.

"I recommend not popping anything when it comes to breakouts," she said.

Instead, she advises to simply keep up with the cleansing process and stay consistent with it. "And drink a lot of water," Thompson said.

"Water is going to help clear out your skin, too, and then it will look more glowing and youthful, so water is a must."