Pimples are clinically known as acne, and sudden breakouts can be caused by endocrine disorders, hypersecretion of sebaceous glands, hyperkeratosis of the follicular epithelium, and Propionibacterium acnes infection. 1. Endocrine disorders: endocrine disorders may also cause sudden breakouts. For example, patients with polycystic ovary syndrome may experience this condition. Some women will also have acne before and after each menstrual period, generally and before and after menstruation estrogen decreases, the proportion of androgens in the body correspondingly increases, affecting the function of the sebaceous glands of the hair follicles. 2. Sebaceous gland hypersecretion: in addition to hormonal influence, sebaceous gland secretion will also be affected by lifestyle habits, such as the intake of high sugar, high oil, spicy and stimulating food, late at night, etc. will also lead to excessive secretion of sebaceous glands, which will lead to popping acne. 3. Excessive follicular epithelial keratinization: metabolites and other stimulation of follicular epithelial cell proliferation and hyperkeratosis, resulting in blockage of pore openings, sebum excretion is impeded, thus causing acne. 4. Propionibacterium acnes infection: Due to the large amount of sebum secretion, Propionibacterium acnes multiplies and leads to inflammatory reaction, which eventually causes acne. If more pimples suddenly appear on the skin, it is recommended to consult a doctor in time and follow the doctor’s instructions for examination and treatment.