There are many factors to consider when menstrual volume is low and the color is light: First, it is related to dietary habits, because some women eat spicy and stimulating food a week before or at the arrival of menstruation, including eating cold food can cause poor flow of menstrual blood, so it can lead to low menstrual volume and even color change. When there are endocrine hormone diseases, such as hypothyroidism, hyperprolactinemia, or even polycystic ovary syndrome, it can cause low menstrual volume and even change the color of menstruation. Third, some women in the case of pregnancy, due to changes in hormone levels, especially progesterone, estrogen, HCG decline can cause a small amount of bleeding, so be sure to exclude whether you have conception, and if necessary, fertility preservation treatment.