If the sebaceous glands secrete a large amount of sebum, it cannot be effectively discharged from the surface of the skin and may accumulate inside the sebaceous ducts to form pimples. There are many factors that stimulate the formation of acne. If the patient squeezes the skin locally, it may cause the inflammation of local acne to increase, so it in turn aggravates the formation of acne. If the patient stays up late often, the sebaceous glands may become more active and the acne condition may worsen. Or, if the patient eats spicy and stimulating foods or fried foods, this may lead to the growth and increase of acne in the area. Inflammatory manifestations may also occur if the area is infected with localized pathogenic bacteria.