WHAT CAUSES ACNE: Here you'll find a list of 13 common acne causes, why these activities or habits are cause acne, and how to simply fix these issues. Cosmopolitan.com talked to aesthetician and cosmetic chemist Mary Schook who told us everything you need to know to get glowing, blemish-free, and flawless skin. Click through for all her tips and acne remedies and treatments.