Sebaceous glands and heredity are the main causes of acne Acne occurs with a hormonal shift during puberty or pregnancy and with stress, other factors are not proven. Certainly, it is most often teenagers who are affected by this problem. The cause of the appearance of acne is considered during puberty, an increase in sebum production as a result of a hormonal surge. What is sebum? And this is the secret of the sebaceous glands☝🏻 Other possible causes include clogging of the sebaceous ducts with skin care products and infestation with parasitic mites of the genus glandularis.