Having an irregular menstrual cycle is one of the most common reasons women see a doctor, according to the American Congress of Obstetricians and Gynecologists. An irregular cycle has many causes and can occur at any age after the onset of menstruation. Some causes are serious and require treatment, while others are common to specific age groups as part of the natural aging process.
Function
The menstrual cycle is part of the reproductive process in a woman. Each month, the body prepares the womb (uterus) for pregnancy. If no pregnancy occurs, the body sheds the prepared lining of the womb, causing menstrual blood to pass through the small opening in the cervix and on through the vagina. This shedding of the uterine lining and associated blood is called a menstrual period.
Misconceptions
A menstrual cycle is not the same as a menstrual period. A menstrual cycle is the number of days from the first day of bleeding one month to the first day of bleeding the next month. A menstrual period is the number of days of actual bleeding each month. The average menstrual cycle is 28 days, according to the National Women's Health Information Center, but it can range from 21 to 35 days. A menstrual period usually lasts from three to five days, but anywhere from two to seven days is normal.
Identification
When a woman has a menstrual period at regular intervals, she has a regular menstrual cycle. When abnormal bleeding occurs or when her menstrual cycle is longer than 35 days or shorter than 21 days, she has an irregular cycle. Abnormal bleeding, as described by the American Congress of Obstetricians and Gynecologists, is bleeding that occurs between periods, after sex or after menopause, spotting that occurs anytime during the menstrual cycle, and bleeding heavier than normal or for longer than normal.
Features
It is common for a woman to have an irregular menstrual cycle at certain times during her life. It often takes a few years for a young girl's body to settle into a regular cycle when she first starts to menstruate, which usually occurs at around 9 to 16 years of age. A woman's cycle often gets shorter around age 35, and even shorter as she approaches menopause--typically around age 50. During this time, it is also normal to skip periods or for bleeding to be heavier or lighter than usual.
Causes
Irregular menstrual periods, according to the University of Illinois at Urbana-Champaign McKinley Health Center, are usually a symptom of some underlying physical condition or hormonal imbalance. Weighing too much or too little can affect your periods, as can a sudden change in physical exercise levels. Other common causes of abnormal bleeding include emotional stress, physical illness, medications, problems associated with birth control methods, uterine polyps and certain types of cancer.
