Menstruation is the shedding of endometrium and bleeding affected by the periodic change of sex hormones secreted by the ovarian. Menstruation is condition or changes which occur in the woman's body monthly.
The duration of menstruation is generally 3-7 days and the averaged is 5 days.
Menstruation is accompanied with menstrual cramps , fever , abdominal pains, back pain in some ladies.
Girls do not have menarche and sexual charactertics developed during puberty (such as breast development) mostly at the age of 13.
The menstrual cycle can or will be affected by being too fat or too thin or taking birth control pills ,all these can affect menstrual cycle.
Women between age 40-50 usually enter the age of menopause , such women won't be able to conceive or give birth again.
Menstruation can reflect some health problems of female body , we can predict the time ovulation and help fertilizer. It is important to keep the menstruation record by the use of menstrual calendar