Prolactin is a peptide hormone, also known clinically as prolactin, that is secreted by the pituitary gland and, as the name implies, has the primary function of promoting breast development and lactation during late pregnancy and lactation. For non-pregnant women, serum prolactin levels should not exceed 20 ng/mL, and hyperprolactinemia is highly suspected if the clinical level of prolactin is greater than 100 ng/mL. If it is greater than 200ng/mL, the diagnosis of hyperprolactinemia is basically confirmed and there may be a pituitary microadenoma in the pituitary gland. If prolactin is elevated, it mainly causes a series of endocrine problems, which can lead to menstrual irregularities in women; there is lactation, and if a woman’s bilateral breasts are squeezed, milk can be seen and fat droplets can be seen under the microscope; because of the long-term decrease in estrogen levels, it may cause a decrease in bone mass, leading to osteoporosis. Therefore, the measurement of prolactin is mainly to exclude the presence of pituitary disorders.