A period is generally referred to as menstruation, and there may be a slight increase in weight due to changes in hormone levels in the body prior to menstruation. If the weight gain is more pronounced, it may be abnormal. The relatively high levels of estrogen and progesterone in a woman’s body prior to menstruation may lead to water and sodium retention, which may cause a significant increase in tissue fluid and may result in a slight weight gain. If a woman’s weight gain is more obvious, especially when edema occurs, it may be a manifestation of various organic diseases such as liver disease, heart disease, kidney disease, etc., which need to be clearly identified with physiological edema caused by hormonal changes in the body before menstruation, and it is recommended to go to the hospital so as to avoid misunderstanding of the condition and serious consequences.