What Is the Average Length of a Menstrual Cycle?

A menstrual cycle is the process most women go through each month. A woman's body prepares an egg to become a potential baby. If the egg is not fertilized the body discards it. This process takes place from the start of menstruation at puberty until the cessation of menstruation after menopause. Normal cycle lengths vary from woman to woman.

Young Women

• When a young woman first starts to menstruate her cycles may vary in length. The times between her periods may be as little as two weeks in one month and then not come again for a month or two. This is normal in adolescent girls. If the bleeding continues for more than a week or is very heavy, consult with a gynecologist. This could be the sign of an underlying problem.

Peak Childbearing Years

• During a woman's peak fertility years a typical cycle is between 21 days and 35 days. Ovulation may be delayed because of stress. This is also normal. Cycles of less than 21 days or longer than 35 days may be a sign of an underlying hormonal problem. Contact an gynecologist if the situation persists for more than three months.

Later Years

• As a woman approaches menopause her menstrual period may come once every two weeks or not show up until two months later. This is also normal. Continue to use contraception because it is possible to get pregnant until your periods have ceased.

Cycle Mechanics

• Each month a woman will typically get her period for three to five days. Normal bleeding should not soak more than a menstrual pad per hour. Once this time has ended the woman the production of fertile cervical fluid may start several days later. Fertile cervical fluid looks like clear egg white on a tissue. This is a sign of impending ovulation. After ovulation, the women usually cannot get pregnant that month. This is called the luteal phase of her cycle. A normal luteal phase is 10 to 16 days. After this phase is over her period should reappear and the cycle starts all over again.

Problems

• A woman of childbearing age may not have a period for a wide variety of reasons. Such causes include ovarian dysfunction, a functional cyst or an underlying condition such as Polycystic Ovarian Syndrome. If menstrual problems continue consult with a gynecologist. Even if you are not planning to get pregnant, absent or scant menses may be a sign of a more serious medical condition.