The 18-year-old menstruation delayed 10 days is not normal, if you have sex must be ruled out whether the pregnancy, but also may be due to endocrine disorders. A menstrual cycle is generally 21-35 days, an average of 28 days, the menstrual period a week in advance and delayed a week is a normal physiological phenomenon. 18-year-old menstrual delayed 10 days is not normal, if you have had a history of sexual intercourse and did not take contraceptive measures, to first rule out the possibility of pregnancy. It may also be related to many factors such as hormone level disorders in the body, stressful studies, frequent late nights, dieting and weight loss. It is suggested that patients can first relax, change their bad habits, and then wait patiently for a few days. If it still does not come, it is recommended to consult a doctor in time, improve the relevant examination, under the guidance of the doctor to clarify the cause of the disease, targeted treatment.