A 10-day delay in menstruation is usually abnormal. A normal menstrual cycle lasts from 21 to 35 days, with an average of 28 to 30 days. Normal menstruation is a cyclical shedding of the endometrium that occurs under the influence of hormones in the body. There are many reasons why a woman may experience delayed menstruation. It may be caused by getting cold before or after the menstrual period or by high mood swings, frequent anger and staying up late. If menstruation is delayed for 10 days since the first menstruation or occasionally, without any change in the quantity, color or quality of menstruation, it is mostly due to individual factors or affective factors. If a woman of childbearing age has a period that is 10 days later than before or after, the possibility of pregnancy should be ruled out first. If there is a prolonged delay in menstruation, it is considered as menstrual disorder. If there is a combination of increased menstrual flow and prolonged menstruation, you need to go to the hospital for ultrasound examination for uterine fibroids, endometrial polyps and other lesions. Therefore, if your period is delayed for 10 days, you need to actively look for the cause, whether it is due to physiological or pathological factors, and take appropriate treatment according to the specific situation.