One cause is hyperprolactinemia, or excessive prolactin secretion by pituitary lactotroph cells, which is frequently seen with a benign pituitary tumor called a prolactinoma.

一个原因是高泌乳素血症，即垂体泌乳素细胞分泌过多泌乳素，大多并发良性的垂体肿瘤，称为泌乳素瘤。

If blood levels of TSH are normal or high, this points to a pituitary tumor which can be confirmed with an injection a thyrotropin-releasing hormone.

如果血液中TSH的水平正常或升高，则考虑垂体肿瘤，这可以通过注射促甲状腺激素释放激素来确定。