The desire to vomit before the period can occur in the following situations: 1, the most common case is the stress reaction, because some women may experience mental tension or anxiety before the period, these mental stimuli will act on the autonomic nerves of the gastrointestinal tract, thus causing temporary disorders in the function of the gastrointestinal tract, so that the smooth muscle contraction of the intestine aggravates the feeling of nausea and vomiting; 2, because of the poor physical condition of women, due to the period It is a physiological reaction for women with both advantages and disadvantages. The disadvantage is that it can make women lose nutrients, such as iron, vitamins, proteins, etc. Some women may have allergic reactions to menstruation, these reactions can lead to disorders in women’s digestive function, making women feel like vomiting; 3, for some women before the period want to vomit is a normal physiological reaction, not a female disease or physical abnormalities.