You can eat some barley in small quantities when you have your period. But the amount should not be too much, because barley is cold, although it has a diuretic, spleen function, but in the period should not eat more, may induce dysmenorrhea, leading to increased menstruation, prolonged period. It is best to pay attention to supplemental nutrition during menstruation, drink brown sugar and ginger water, eat an appropriate amount of red dates, chicken liver and other foods to replenish blood, never eat spicy and stimulating food, pay attention not to eat cold food, do not touch cold water, try to keep the abdomen warm. You should also avoid strenuous exercise during menstruation to avoid lower abdominal pain and low menstrual flow, and prohibit sexual intercourse during menstruation to avoid inducing vaginitis and pelvic inflammatory disease, and endometriosis may occur if it leads to menstrual reflux. Therefore, menstruation is a relatively fragile phase, so it is important to pay attention to these issues.