Regular vacation refers to menstruation. The first day of menstruation is brown and the second day is gone. Consider that it is related to cold, endocrine disorders, pregnancy-related diseases, and multiple uterine operations. 1. Cold: If a woman is cold and drinks cold or gets wet in the rain or water before the onset of menstruation, it will easily lead to poor menstrual blood flow, which will result in a small amount of menstruation, dark color, menstrual cramps and other discomforts. 2. Endocrine disorders: If a woman is under stress or has gynecological endocrine diseases such as polycystic ovary syndrome or premature ovarian failure, the endocrine disorders will affect the discharge of follicles from the ovaries and the stripping of the uterine endothelium, and therefore, she will have a scanty menstrual flow. 3. Pregnancy-related diseases: for women of childbearing age, if they have normal sexual life, there is a possibility of pregnancy, and if there is bleeding that is different from normal menstruation, then we should be vigilant about the occurrence of pre-menstrual abortion and ectopic pregnancy. 4. Multiple uterine operations: For women who have undergone multiple uterine operations such as abortion, curettage, removal of the IUD, etc., the endometrium has been damaged to varying degrees, and the endometrium is the material basis of menstrual blood, so there will be a small amount of menstruation, shortening of menstrual period and other manifestations. For women whose menstruation is brown on the first day and disappears on the second day, it is recommended that they go to the gynecology department of a regular hospital, improve the sex hormone, blood HCG, ultrasound and other related examinations, and then take active treatment under the guidance of the doctor after clarifying the cause of the disease.