Many people assume acne is an issue that primarily affects teens. But, plenty of people experience acne well into their adulthood. It tends to be more common for those who had acne during adolescence, says Dr. Anar Mikailov, a board-certified dermatologist and the founder of KP Away. However, even if you didn’t have acne in your formative years, there are plenty of reasons why pimples are starting to pop up as an adult. Understanding what’s causing your breakouts can help keep them at bay. We dive into the science behind adult acne below, plus how to treat it.