Acne refers to acne in medicine. There are many reasons for acne during physiological period, such as abnormal hormone secretion, excessive emotional fluctuation, blockage of hair follicles, improper diet and so on. 1. Abnormal hormone secretion: During menstruation, estrogen secretion in women’s bodies is relatively high, which can affect the secretion of sebum on the face, leading to excessive sebaceous glands on the face, blocking the hair follicles and causing acne. 2. Excessive mood swings: During menstruation, some women may experience menstrual syndrome, which can cause personality and emotional changes, such as depression, anxiety, temper, etc., can also affect the body’s endocrine level, resulting in the appearance of acne. 3. Hair follicle blockage: some women usually do not pay attention to skin care and cleansing, resulting in local skin follicles are blocked by dirt, oil can not be excreted, coupled with a large number of Propionibacterium acnes reproduction and growth, which can cause the appearance of acne. 4. Improper diet: During menstruation, some women prefer to eat some high-calorie foods, such as fried foods, high sugar sweets, etc., which can increase the secretion of skin oil, more likely to induce acne. There are other reasons for acne during physiological period, it is recommended that patients go to the hospital in a timely manner, under the guidance of the doctor to regulate and treat.