The menstruation cycle refers to the female reproductive cycle. It includes ovulation and menstruation, and usually occurs regularly each month. Most women begin their menstruation cycle in early adolescence, and continue to experience the cycle regularly until menopause, at about age 50. The typical menstruation cycle lasts 21 to 35 days, with the average being 28 days. Ovulation typically occurs halfway through the cycle, and the menstrual period usually occurs at the end of the cycle.
When a young girl has her first menstrual period, or menarche, she is generally considered to be fertile. Most girls experience menarche sometime between the ages of eight and 15. The physical changes that accompany puberty generally begin about two years before menarche.
The reproductive cycle known as the menstruation cycle generally consists of more than just the menstrual period. The average menstrual cycle lasts 28 days. On average, ovulation occurs on the 14th day of the menstrual cycle. A women is considered most likely to conceive on days 11 to 14 of the average menstrual cycle.
During the first days of the menstrual cycle, the uterine lining of a fertile woman normally becomes thick, so that a fertilized egg can potentially implant itself and begin to grow into a fetus. If the woman does not conceive during a given menstruation cycle, then the uterus will generally expel its lining, along with the unfertilized egg. The expulsion of the uterine lining usually results in a period of vaginal bleeding that can last for two to seven days. This vaginal bleeding may be heavy or light, and is often accompanied by painful cramps and other physical symptoms, including bloating, fatigue, and mood swings. These symptoms are considered normal symptoms of menstruation, and can usually be eased with a healthy diet, regular exercise, and stress management activities.
The period of vaginal bleeding known as the menstrual period is generally considered the final step in the menstrual cycle. Once the menstrual period has ended, the menstruation cycle typically begins anew. Estrogen levels in the fertile woman's body typically rise during the first two weeks of the cycle. This increase in estrogen levels is considered responsible for the gradual thickening of the uterine lining, and, eventually, for ovulation. Most women reach the onset of menopause between the ages of 45 and 50, when menstruation cycles can lengthen and become irregular, leading to eventual cessation of ovulation and menstruation.
