What are the symptoms of too little or too much prolactin?
There are usually few symptoms and few problems. The exception is after pregnancy, when a lack of prolactin may mean that the mother does not produce breast milk. However, unlike other pituitary hormones, prolactin is controlled by the secretion of a compound by the hypothalamus which acts as a brake on the pituitary’s secretion of prolactin. In the case of pituitary tumours that decrease access of hypothalamic hormones to the pituitary gland, this brake is reduced and thus the secretion of prolactin increases. This means that patients with hypopituitarism may actually suffer from excessive levels of prolactin in spite of being deficient in other hormones. A high prolactin level may decrease libido and interfere with normal sex hormone levels and periods, or erections.
