Hypothalamic disease, craniopharyngioma, inflammation and other lesions affect the secretion of prolactin inhibitory factor (PIF), leading to the elevation of hyperprolactinemia. 2.Pituitary disorders are the most common cause of hyperprolactinemia, with pituitary prolactinoma being the most common. more than 1/3 of the patients have pituitary microadenomas (<1cm in diameter). Empty butterfly saddle syndrome can also increase serum prolactin. 3.Primary hypothyroidism The increase of thyrotropin-releasing hormone stimulates the secretion of prolactin in the pituitary. Idiopathic hyperprolactinemia Increased serum prolactin, mostly 2.73～4.55nmol/L, but no pituitary or central nervous system disease is found. In some patients, pituitary microadenomas are found several years later. 5.Other polycystic ovary syndrome, long-term antipsychotics and antidepressants can cause elevated serum prolactin. Clinical manifestations 1, menstrual disorders and infertility: more than 85% of patients have menstrual disorders. Patients of reproductive age may not ovulate or shorten the luteal phase, which may be manifested as scanty or sparse menstruation or even amenorrhea. Primary amenorrhea may occur in pre-pubertal or early pubertal women, and secondary amenorrhea is more common after childbearing years. Anovulation can lead to infertility. 2.Milk overflow: it is one of the characteristics of this disease. About 2/3 of patients with amenorrhea-milk overflow syndrome have hyperprolactinemia, and 1/3 of them have pituitary microadenoma. Breastfeeding is usually characterized by the discharge or extrusion of non-bloody milky or clear fluid from both breasts. Headache, blurred vision and visual impairment: when pituitary adenoma increases significantly, headache, blurred vision, vomiting, visual field defect and motor nerve paralysis may occur due to the obstruction of cerebrospinal fluid reflux and the pressure on the surrounding brain tissues and optic nerve. 4. Sexual function changes: due to the suppression of pituitary LH and FSH secretion, a low estrogen state occurs, manifested by thinning or atrophy of vaginal wall, reduced secretion, and decreased libido. Diagnosis 1. Clinical symptoms: serum prolactin should be tested for clinical manifestations of menstrual disorders and infertility, breast milk overflow, amenorrhea, hirsutism, and delayed puberty. 2, hematological examination: serum prolactin > 1.14nmol / L (25ug / L) can be diagnosed as hyperprolactinemia. The test is best done in the morning from 9 to 12 o’clock. 3.Imaging examination: when serum prolactin>4.55nmol/L(100ug/L), MRI examination of pituitary gland should be carried out to clarify whether there is pituitary microadenoma or adenoma. 4, fundus examination: because pituitary adenoma can invade and/or compress the optic cross, causing optic papillae edema; also because the tumor can compress the optic cross and lead to visual field loss, therefore, fundus and visual field examination can help to determine the size and location of pituitary adenoma, especially for pregnant women. Treatment After diagnosis, the tumor should be treated with medication, surgery and radiotherapy. (1) Bromocriptine mesylate: it is a peptide ergot alkaloid, which selectively agonizes dopamine receptors and can effectively reduce prolactin. Bromocriptine can inhibit the increase of prolactin level caused by function or tumor. Bromocriptine treatment reduces tumor size and restores menstruation and fertility in amenorrheic-overflow women. In the treatment of pituitary microadenomas, the commonly used method is as follows: week 1, 1.25mg once a night; week 2, 1.25mg twice a day; week 3, 1.25mg daily in the morning, and 2.5mg every night; week 4 and beyond, 2.5mg twice a day, for a 3-month course of treatment. The main side effects include nausea, headache, dizziness, fatigue, drowsiness, constipation, upright hypotension, etc., which may disappear on their own after a few days of administration. The new bromocriptine long-acting injection (parlodel) can overcome the gastrointestinal dysfunction caused by oral administration. Usage is 50-100mg, injection every 28 days, the starting dose is 50mg. (2) Quinagolix: dopamine agonist acting on dopamine D2 receptors. Mostly used when side effects of bromocriptine mesylate are intolerable. Take 25 mg daily for 3 days, then increase by 25 mg every 3 days until optimal effect is obtained. (3) Vitamin B6: 20-30mg orally 3 times daily. It is synergistic with bromocriptine mesylate. 2.Surgical treatment: When the pituitary tumor produces obvious compression and neurological symptoms or drug treatment is ineffective, surgical resection of the tumor should be considered. Short-term administration of bromocriptine before surgery can reduce the size of pituitary tumor and intraoperative bleeding, which can help to improve the therapeutic effect. 3.Radiation therapy: it is used for those who cannot insist on or tolerate drug treatment; those who are unwilling to have surgery; those who cannot tolerate surgery. Radiotherapy is slow to show effect and may cause pituitary hypoplasia, optic nerve damage, tumor-induced complications, and it is not recommended to use radiotherapy alone.