There are several reasons for nausea and vomiting during menstruation: First, it is related to psychological factors. The second reason is that women have low blood pressure. For women with low blood pressure, they will show weakness in their limbs and sometimes dizziness, which will be aggravated when they have menstruation, causing weakness in their limbs, nausea and vomiting. The third reason is that women have PMS, which means that women start to show symptoms of discomfort one week before their menstruation, and the symptoms are more serious during menstruation, showing emotional irritability and depression, and physical headache and regurgitation.