Although acne usually starts in adolescence, it is not uncommon for it to extend into adulthood. Teenage acne generally consists of blackheads and whiteheads on the T-zone—the forehead, nose, and chin. Adult acne tends to be more inflamed, with white and pink bumps appearing all over the face.

Acne is often hereditary, but hormonal fluctuations typically trigger flare-ups. This is why acne often begins with puberty and why some women experience breakouts during menstrual cycles, pregnancy, perimenopause, and menopause. Because of differing hormone levels, male acne tends to be more severe while female acne is more often chronic and on lower parts of the face. For those prone to acne, stress can also trigger breakouts.

Acne begins below the surface and is not caused by dirty skin, which is why washing too frequently or vigorously can cause further irritation. Wash two times daily, adding another wash when exercising or perspiring, or if you have oily skin. Resist the urge to pop pimples, which will lead to greater inflammation and possible scarring. Over-the-counter products that contain salicylic acid or benzoyl peroxide are effective for mild skin issues, while topical retinoids such as tretinoin (synthetic version of vitamin A) peel the outer layer of skin, unclog pores, and prevent future breakouts. A dermatologist can evaluate the type of pimples and triggers to identify the best treatment for you.

–Diane Berson, MD, clinical assistant professor at Weill Cornell Medical College of Cornell University, and board member of the American Acne and Rosacea Society,New York