The normal time for a woman to have her first menstruation is between 11 and 16 years old. If a woman has her first menstruation before the age of 11, she is usually precocious, which may affect the physical development of the girl and may result in a shorter height, requiring timely examination and treatment. If you are more than 16 years old and still do not have menstruation, and no secondary sex characteristics development, usually belong to congenital amenorrhea, you need to go to the hospital as soon as possible to do a check, may be due to congenital developmental abnormalities, may also be caused by chromosomal abnormalities, need to carry out ultrasound examination, gynecological examination, and chromosomal examination, etc., according to the results of the examination as soon as possible for treatment, because women do not have menstruation is a disease that affects the whole life.