Closed pimples on the face are a type of acne, and there are several reasons for their onset: they may be related to high or relatively high levels of androgens in the body, which can cause the sebaceous glands to secrete too much oil. Some sebaceous gland ducts are abnormally keratinized, resulting in the blockage of sebaceous ducts and the accumulation of sebum in the sebaceous glands of hair follicles, which gradually increases in size and forms closed pimples. Others are related to inappropriate cosmetics, such as the application of powder cosmetics that cause the sebaceous glands to become blocked, or some cosmetics that contain alcohol or hormones, which over time can also lead to closed acne or common acne.