The menstrual cycle is repeated every month throughout the reproductive years, generally between the ages of eleven and fifty.
Menstruation is the shedding of a bloody fluid from the uterus or womb.
About every month, the uterus or womb builds up a lining to receive a fertilized egg. If the egg is not fertilized by a male sperm cell, the lining is not needed, so it is shed. This lining is the menstrual fluid and comes out of your body through the vaginal opening. Menstruation is only a small part of the entire process known as puberty or the process of growing up to be an adult. The first sign of puberty occurs when you begin to develop breasts and pubic hair.