There are several reasons for women to have menstrual stomach pain: First, it may be gynecological inflammation, such as common cervicitis, endometritis, pelvic inflammatory disease, vaginitis, ovarian inflammatory disease, tubal inflammatory disease, etc. When women suffer from these gynecological inflammatory diseases, inflammation can lead to increased permeability of the skin mucosa and blood vessels at the lesion site, which can have an irritating effect on the local nerves and can lead to stomach pain when menstruating. Secondly, it may be due to problems with the endocrine system, because the formation of menstruation is very closely related to the female endocrine system, especially the endocrine system secretion of estrogen, sex hormones, progesterone, follicular estrogen, etc. When the content of these hormones is abnormal, it will lead to the adverse reaction of stomach pain when women have their menstruation. Thirdly, it may be due to women’s emotional problems. Women may experience depression, anxiety, tension, depression and insomnia during menstruation, and these adverse emotional reactions can also indirectly stimulate the autonomic nerves, leading to the symptoms of stomach pain when women have their menstruation.