Menstruation Health Article

Menstruation

The periodic sloughing off of the uterine lining (endometrium) during a woman*s reproductive years.

Approximately once a month, women of childbearing age experience a bloody vaginal discharge known as menstruation. The onset of menstruation (menarche) usually occurs sometime between 11 and 15 years of age (average age is 12.8). The average menstrual cycle lasts approximately 28 days, although anywhere between 20 and 36 days is considered normal. (The menstrual cycle is measured from the first day of one period to the first day of the following period.) Monthly menstruation continues until a woman reaches menopause, which ordinarily occurs between the ages of 45 and 50.

Menstruation is the result of complex hormonal interactions. During the typical menstrual cycle, the ovaries produce estrogen and progesterone, which cause ovulation to occur and the lining of the uterus (endometrium) to build up. If sexual intercourse takes place and a sperm fertilizes the egg (ovum) as it moves through the fallopian tube, the fertilized egg will implant itself in the endometrium and begin developing into a fetus. If no fertilized egg has implanted itself in the endometrium, the secretion of progesterone from the ovaries declines, which causes the endometrium to be sloughed off. Menstruation usually occurs two weeks after ovulation, although irregular periods are common in early adolescence, and menstruation often takes place without ovulation (anovulatory menstrual bleeding). For many girls, it takes a year or two to establish a predictable menstrual pattern. Even after adolescence, a number of physical and emotional factors can throw off the timing of menstruation. These include relationship problems, starting a new job or school, and weight change, among others.

Dysfunctional uterine bleeding (DUB)

Dysfunctional uterine bleeding (DUB) is heavy or prolonged bleeding, usually anovulatory. Heavy bleeding is defined as more than 15 soaked pads or tampons per period, and prolonged bleeding as bleeding that lasts for more than 8-10 days. Although DUB is very common in the first couple of years after menarche, it can be very frightening and should always be reported to a physician. DUB accompanied by dizziness and low blood pressure should be considered a medical emergency. DUB has a number of causes, including hormonal imbalance, sexually transmitted diseases, ectopie pregnancy, hypothyroidism, ovarian cysts, and uterine fibroids or polyps.

Dysmenorrhea

Dysmenorrhea (painful menstruation) is the most common gynecological problem reported by adolescents and the leading cause of absence from school and work. Approximately 75% of women have some degree of pain associated with menstruation, most commonly cramping in the lower abdomen which is most severe on the first day or two of a period. Leg and back pain are also common, as are diarrhea, nausea, fatigue, and headache.

Dysmenorrhea is usually not indicative of serious underlying medical problems. The term primary dysmenorrhea refers to painful periods that are not attributable to any abnormality of the reproductive system. Primary dysmenorrhea is most often caused by prostaglandins (fatty acids) produced in the uterus which cause contractions of the uterus and blood vessels. Prostaglandins may also increase sensitivity to pain. Over-the-counter medications, especially those containing ibuprofen, are often effective for the treatment of primary dysmenorrhea. If non-prescription medication is not effective, a physician may prescribe a drug called a prostaglandin inhibitor. In some cases, an oral contraceptive may be prescribed to prevent ovulation and reduce prostaglandin production.

The term secondary dysmenorrhea refers to painful periods caused by an abnormality of the ovaries, uterus, fallopian tubes, or vagina. If dysmenorrhea does not respond to medication, a physician will investigate other possible causes. The medical evaluation might include ultrasonography (a picture similar to an χ ray created by sound waves) or laparoscopy (a minor surgical procedure). Among adolescents, the most common cause of secondary dysmenorhea is a condition called endometriosis. In endometriosis, cells from the uterine lining (the endometrium) travel to other places in the abdomen such as the fallopian tubes. Other conditions that can lead to dysmenorrhea during adolescence include tumors, malformations, cysts, or inflammation caused by sexually transmitted diseases (STDs).

See also Amenorrhea; Menarche; Ovum; Toxic Shock Syndrome

Books

Avraham, Regina. The Reproductive System, New York : Chelsea House, 1991.

Bell, Ruth, et al. Changing Bodies, Changing Lives. New York: Vintage, 1988.

McCoy, Kathy, and Charles Wibbelsman. The New Teenage Body Book. New York: The Body Press (Putnam), 1992.

Organizations

American College of Obstetricians and Gynecologists
Address: 409 12th Street
Washington, DC 20024
(Brochures about menstruation, pregnancy, and other topics)

—Gail B. Slap, M.D.

University of Pennsylvania School of Medicine