what causes acne and pimples
The cause of acne is not fully understood. Though stress can aggravate acne, it clearly does not cause it. Hormones. Common acne in teenagers starts with an increase in hormone production. During puberty, both boys and girls produce high levels of androgens, the male sex hormones that include testosterone.
This globby mess blocks the skin's pores and bacteria develops, causing a pimple, and then more pimples. The good news is you are in good company: almost everyone suffers from pimples at some point in their lives (I read something about 85%, but how they got that figure is beyond me). Even adults suffer from acne: one in 5 women between the ages of 25 and 40 have adult acne. Adult acne affects more women than men. Another bit of good news: those pimples will disappear post-menopause when your skin loses all those hormones that caused them to flare up in the first place.