Menstruation is the woman’s monthly shedding of the lining of uterus and bleeding with the emergence of cyclical changes in ovarian. The menstrual blood is partly blood and partly tissue from the inside of the uterus, and it flows from the uterus through the cervix and pass out of the body through the vagina. Most menstrual periods last from 3 to 5 days.
Menarche refers to the first menstruation of a girl. It usually happens at the age of 12, but can begins at any time between the age of 11~14. Menarche does not occur till the age of 16, which should be paid attention. The emergence of menstruation is a sign of maturity and also considered to be a sign of fertility.
When you menstruate, there will be a flow of blood from the vagina. It may be brown initially, but will turn to red before it stops completely. Periods may last 4-5 days long, in some cases; it may even take 7 days.