The stomach swelling before menstruation is divided into the following cases: 1. Before each menstruation there is a slight feeling of holding and swelling, most of which is a normal physiological phenomenon. Before and at the time of menstruation, the pelvic cavity is in a state of congestion, when the stomach will feel discomfort. So women before menstruation or menstruation, there may be such a situation, in addition to bloating belly, but also can have a sore back, falling feeling. If the performance is not heavy, belongs to the normal physiological state, do not mind too much can be appropriate exercise but the amount of exercise should not be too much, should also be appropriate rest; 2, dysmenorrhea, that is, holding the feeling of distension is obvious or even pain belongs to the performance of dysmenorrhea. Some women have obvious dysmenorrhea, which is not only painful during menstruation, but also painful before menstruation, and feel suffocating and painful in the stomach during menstruation. This condition should be distinguished as primary or secondary dysmenorrhea. If the symptoms disappear after menstruation, especially after the menstrual blood is discharged smoothly, it is often primary dysmenorrhea, or functional dysmenorrhea. After marriage and childbirth, the opening of the uterus is dilated and the uterus is further developed, the menstrual discharge ability is enhanced, so the discharge of menstrual blood is smooth and no dysmenorrhea occurs at this time; besides primary dysmenorrhea, there is another kind of dysmenorrhea called secondary dysmenorrhea, that is, dysmenorrhea caused by diseases that did not hurt in the past. It is common to have pelvic inflammatory disease, endometriosis, or tumor of the reproductive organs, which can obstruct the discharge of menstrual blood and cause dysmenorrhea. In this case, you should go to the hospital for examination and treatment according to the cause of the disease. Especially in the case of pelvic inflammatory disease, it should be known that dysmenorrhea is sometimes related to pelvic inflammatory disease, in which case it should be detected and treated early in order to control the disease and cure it completely. If the condition develops over a longer period of time, it will be difficult to treat the condition and bring difficulties to female reproduction as well as life. In conclusion, there are three types of abdominal distention that occur before menstruation. One is a mild physiological change that does not require treatment. One type is painful and is a case of dysmenorrhea. In the case of primary dysmenorrhea, it is a functional dysmenorrhea and can be treated with herbs. In the case of secondary dysmenorrhea, the cause needs to be identified and may be related to pelvic inflammatory disease, endometriosis or even gynecological tumors.