There are three common factors for breast milk production: normal physiological reaction, drug stimulation and disease influence. Normal physiological reaction mainly refers to the secretion of lactogenic hormones by women during late pregnancy and lactation due to hormones and continuous sucking stimulation by young children, thus producing milk and flowing through the nipples. Drug stimulation, nervousness, and mental illness may also stimulate breast milk secretion due to long-term use of certain sedative drugs and long-term oral medication for gastric diseases. The milk then overflows through the nipple causing such a situation, and timely examination should be conducted to rule out pituitary gland and other pathologies.