Dysmenorrhea is categorized into primary dysmenorrhea and secondary dysmenorrhea, in which primary dysmenorrhea is related to changes in the organism, uterine curvature and other factors; secondary dysmenorrhea is related to endometriosis, adenomyosis, pelvic adhesions, birth control devices and so on. 1. Primary dysmenorrhea: (1) Changes in the organism: during menstruation, in order to promote the stripping of the endometrium, the body’s content of prostaglandins and contractions increases significantly, and these substances lead to uterine contraction and vascular spasm, so the patient will experience dysmenorrhea. (2) Uterine curvature: If the uterus is excessively tilted and flexed, it will lead to poor discharge of menstrual blood and stimulate uterine contraction, thus dysmenorrhea will also occur. 2. Secondary dysmenorrhea: (1) Endometriosis, myometriosis: these two causes are due to the functional endometrium appeared in places other than the uterine cavity, due to the ectopic endometrium will also be with the ovarian hormone level and cyclic changes, so the localization if combined with congestion, bleeding, will lead to dysmenorrhea. (2) Pelvic adhesions: For women with a history of pelvic inflammatory disease or pelvic surgery, there may be adhesions between the local tissues, thus affecting the normal position and curvature of the uterus, which may lead to dysmenorrhea. (3) Birth control devices: The use of birth control devices may cause damage to the uterus, secondary infection, or the patient’s inability to adapt to the device, and some patients may experience dysmenorrhea. For women with dysmenorrhea, it is recommended that they go to the hospital to improve ultrasound and other related examinations, to clarify the cause of the disease and then actively treat under the guidance of the doctor.