The normal age for a girl to menstruate is between 11 and 13 years old, and it is because a girl’s ovaries are gradually maturing and stabilizing, and will begin to affect the lining of the uterus, resulting in the onset of menstruation. It is normal for girls to menstruate at this age. With the improvement of living standards, many girls develop earlier, and it is common for many girls to menstruate at the age of ten, which is not a problem at this age. If the age of menstruation is further advanced, at 8-9 years old, you need to come to the hospital to rule out precocious puberty. Those who have not menstruated beyond the age of 15 should also be examined to see if the female reproductive system is well developed and if there are any other disorders.