Weight gain before menstruation is considered to be caused by the following possibilities: First, estrogen and progesterone will reach a high level before menstruation, and estrogen will cause an increase in water and sodium retention in the body, which will obviously lead to weight gain, and edema of both lower limbs and intracranial edema can occur before menstruation and cause headaches. Secondly, it is considered to have kidney disease itself, such as chronic nephritis and nephrotic syndrome, which will cause edema before menstruation due to abnormal circulation in the body, resulting in weight gain. Thirdly, it is considered that the appetite is better before menstruation and the diet is too much high protein and high oil food, which leads to the accumulation of body fat and causes weight gain.