It is best not to dye your hair during menstruation for the following reasons: 1, may lead to an increase in menstrual blood, the heat emitted by the instrument used for hair dyeing will lead to heat and sweating on the head, which will easily cause the capillaries in the head to expand, abnormal body hormone secretion, increased endometrial shedding, menstrual bleeding will be more, and may also delay the period. 2, easy to catch a cold, the immunity during menstruation is relatively 3. skin allergy, the skin resistance is weaker during menstruation, skin sensitivity is higher than usual, and some chemical components in the hair dye, skin irritation is greater, easy to cause skin allergy, if the skin is more sensitive, the symptoms will be more serious, do not perm and dye hair during menstruation, head, abdomen to Do keep warm measures.