by Susan Hayes

If you worry about acne, join the club. 79% of teen boys and 89% of teen girls target acne as one of their biggest pains, according to a 1994 American Medical Association study. No wonder. 80% of Americans between ages 11–30 have battled zits at one time or another. So maybe you think you know it all when it comes to acne. Guess again. "The number of misconceptions out there is astounding," says Dr. Linda K. Franks, a New York City dermatologist (doctor who treats skin diseases). Here's the dirt on acne:

What is acne, exactly?

Zits happen when bacteria invades trapped oil in the sebaceous, or oil, gland under your skin (see diagram below). The body's largest oil glands are on your face (called the T-zone — forehead, nose, and chin), neck, chest, and upper back.

Some teens sprout a few pimples. Others battle serious acne. Why?

As certain hormones (substances that control body functions) become more active in the teen years, your oil glands churn out more oil. But the severity of acne depends on whether or not your pores get easily blocked — a genetic condition you inherit from your parents.

Does gobbling candy bars or French fries cause pimples to pop?

"There's no link between diet and acne," says Franks. Surprised? Scientists have so far found no concrete connection between what you eat and the pimples you get.

Whiteheads, blackheads, pimples — what's the difference?

If oily cells stay trapped beneath the skin's surface, you may get a whitehead. If the cells reach the skin surface, they mix with melanin (skin pigment) and turn dark — presto, blackhead. But when normal skin bacteria invade a clogged pore, infection-fighting white blood cells rush to the rescue. Then walls of a hair follicle stretch and rupture. End result: a zit.

What can you do to zap zits?

Wash (don't scrub!) your face daily with a gentle soap or liquid cleanser. Two effective zitzappers in anti-acne products: salicylic acid, which helps unblock pores, and benzoyl peroxide, an antiseptic that dries out pimples and keeps infection-causing bacteria under control. Never pick or squeeze pimples! You can scar yourself for life. If pimples don't vanish after several weeks of using over-the-counter products, or if you sprout several large, deep, red cysts, consult a dermatologist.