Regardless of whether your teen years are in your rear-view mirror, or you're still in school, suffering from acne breakouts is a major downer. It may not seem fair, but you're certainly not alone. Once considered only a "teenage concern," today acne is one of the most common skin condition affecting adults as well. Acne is a complex problem with a number of possible causes. Culprits include hormonal shifts, cosmetics, pollution, changing birth control pills and stress. Of all the possible triggers, stress may actually be one of the most significant, according to recent studies by Stanford University and the Wake Forest School of Medicine. This means that anxiety-inducing situations - a major test, a first date or an important job interview - could lead to breakouts. However, even day-to-day obligations can be stressful enough to cause regular flair ups.