Menstruation (a period) is a major stage of puberty in girls; it's one of the many physical signs that a girl is turning into a woman. And like a lot of the other changes associated with puberty. Some girls can't wait to start their periods, where AS others may feel afraid or anxious.
When girls begin to go through puberty (usually starting between the ages of 8 and 13), their bodies and minds change in many ways. The hormones in their bodies stimulate new physical development, such as growth and breast development. About 2 to 2½ years after a girl's breasts begin to develop, she usually gets her first menstrual period.
The start of periods is known as menarche. Menarche doesn't happen until all the parts of a girl's reproductive system have matured and are working together.
As a girl matures and enters puberty, the pituitary gland releases hormones that stimulate the ovaries to produce other hormones called estrogen and progesterone. These hormones have many effects on a girl's body, including physical maturation, growth, and emotions. About once a month, i n the days before ovulation, the hormone estrogen stimulates the uterus to build up its lining with extra blood and tissue, making the walls of the uterus thick and cushioned
Menorrhagia : when a girl has a very heavy periods with excess bleeding.
Oligomenorrhea : when a girl misses or has infrequent periods, even though she's been menstruating for a while and isn't pregnant .
Amenorrhea : when a girl hasn't started her period by the time she is 16 years old or 3 years after starting puberty, has not developed signs of puberty by age 14, or has had normal periods but has stopped menstruating for some reason other than pregnancy.
Vulvovaginitis: a n inflammation of the vulva and vagina. It may be caused by irritating substances (such as laundry soaps or bubble baths). Poor personal hygiene may also cause this problem. Symptoms include redness and itching in the vaginal and vulvar areas and sometimes vaginal discharge.
nonmenstrual vaginal bleeding: a condition in which the mucous membranes of the urethra protrude into the vagina and form a tiny, donut-shaped mass of tissue that bleeds easily.