Acne can be caused by many factors. These possibilities include: Genes and hereditary factors, which are likely if your parents also had acne. Hormone activity from androgens, such as when going through puberty, menstrual cycles, or menopause. Also related to hormone activity, acne can be caused by: Polycystic ovary syndrome Contraceptives, since they cause androgen level changes Medications that cause acne (if you are taking any of these, the side effects should have been explained to you). Uncleansed dirt and external oil coming in contact with the skin. Comedogenic makeup and skin creams (often because they are oil-based). Stress and diet. Though, these factors as causes of acne are debated, and hard to prove. Environmental factors, such as humidity and oil contact in the workplace.