menstruation

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Periodic sloughing of the uterine lining in women of reproductive age. Menstrual bleeding indicates the first day of the menstrual cycle, which lasts an average of 27–30 days, although ranges of 21–60 days have been recorded. Menarche, the onset of menstruation, occurs between the ages of 9 and 16. The majority of females begin menstruating at ages 12–14. During the first few years, the duration and intensity of menstrual flow and the total cycle length may be quite variable, but regularity is gradually established. Cessation of menses, or menopause, occurs at an average age of 51, with a range of 42–60 years.

The menstrual cycle consists of cyclic changes in both the ovary and the uterus. These changes are controlled by the interaction of several hormones including follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are secreted by the anterior pituitary, and the steroid hormones estrogen and progesterone, which are secreted by follicles in the ovary. At the beginning of the cycle, the follicle is stimulated by FSH. In response, it grows and secretes estrogen. The amount of estrogen secretion increases rapidly near the middle of the cycle. Estrogen, in turn, stimulates growth of the uterine lining (mucosa), which becomes thicker and fills with blood vessels. In midcycle, the rapid increase in estrogen causes a massive surge of LH release and a smaller release of FSH from the pituitary. This surge causes ovulation, which is the release of the ovum from the follicle. After ovulation, the follicle undergoes rapid changes and is then called a corpus luteum, which secretes progesterone in response to LH stimulation. Progesterone and estrogen together cause a further thickening of the uterine mucosa, preparing the uterus for pregnancy. If pregnancy does not occur, the corpus luteum degenerates, the uterine mucosa sloughs off, and the cycle begins again.

There is no menstrual bleeding during pregnancy, as the uterine mucosa is needed for the maintenance of pregnancy. This amenorrhea, or lack of normal ovarian function, sometimes continues during nursing.

The discharge of blood and fragments of the uterine wall at approximately monthly intervals during the menstrual cycle. The cycles begin at puberty and end at menopause. During menstruation, most women experience feelings of lassitude or fatigue. Women who exercise strenuously are particularly susceptible to iron-deficiency anaemia because of blood losses. They need higher than normal levels of haemoglobin to carry the oxygen they require for exercise. Athletes can take hormones, such as oestrogen, progesterone, and progestogens, to adjust the time of menstruation. Although most sports women perform less well during menstruation, a few perform better. World and Olympic titles have been won at all stages of the menstrual cycle.

The effects of exercise on menstruation varies from one individual to another but reported effects include the following:

• delayed onset of the first menstruation, common in participants in sports such as gymnastics that require a slim physique
• shortening of cycle by up to 4 days
• reduced menstrual pain associated with regular aerobic exercise
• increased failure to ovulate or menstruate in up to 50 per cent of competitive track and field athletes.

See also amenorrhoea and premenstrual tension.

Menstruation is the periodic shedding of the endometrium (lining of the uterus) accompanied by blood loss, that identifies the reproductive years of a woman's life. The first menstruation (menarche) usually occurs at puberty (typically between the ages of 11 and 16) and menstrual periods continue until the menopause around the age of 45-50. However, menstruation does not occur during pregnancy and can be suppressed or disrupted in women who are breast-feeding. This was noted by the scientist and philosopher, Aristotle (384-22 bc), who believed that pregnant women did not menstruate because the seed of the male caused blood to coagulate into an egg from which the fetus developed. Milk was also thought to be formed from menstrual blood because of the absence of menstruation in lactating women.

The old ideas as to why women menstruate stemmed from the teachings of Hippocrates (c.400 bc) who believed that health was governed by the balance of the four body fluids or humours — blood, phlegm, black bile, and yellow bile. Thus menstruation was seen as a means of getting rid of excess blood to prevent the body filling with this humour, upsetting the balance and causing illness. This theory was finally disproved by John Davidge in 1814, who pointed out that a woman might only lose a few teaspoons of blood in a typical menstrual flow, while the loss of a much greater amount of blood through blood-letting (cutting the veins) did not prevent menstruation. He concluded that menstruation, rather than being a means of getting rid of excess blood, could be attributed to some odd condition of the ovaries which excited the blood vessels of the womb. In essence his premise was correct.

Menstruation is the culmination of a complex series of hormonal events associated with the cyclical production of a mature egg within the ovary and the release of this egg for fertilization. In the first half of the menstrual cycle, ovarian follicles, containing an egg, develop, and produce increasing amounts of oestrogen. This sex hormone stimulates a build-up of the lining of the womb and the growth of spiral arteries into this thickened lining. After ovulation, which occurs around day 14 of the cycle, the empty follicle in the ovary becomes a corpus luteum. This produces high concentrations of progesterone and some oestrogen. The progesterone further increases the thickness of the uterine lining and causes it to secrete a fluid which will nourish a fertilized egg and encourage implantation of the embryo. If fertilization does not occur the corpus luteum breaks down towards the end of the cycle and so the endometrium loses its hormonal support from the ovary. As a consequence the endometrium literally dies, and the cells of this lining are shed along with some loss of blood from the spiral arteries which have grown into the lining of the womb. Menstrual bleeding usually lasts 3-7 days, although endometrial regeneration can begin as early as the third day after the beginning of menstruation. Interestingly, only in man, apes, and Old World monkeys is the endometrium shed. In most other mammals the endometrium is resorbed at the end of each cycle and there is no bleeding — this is probably related to the absence of spiral arteries.

While the shedding of the uterine lining actually signifies the end of each reproductive cycle, the first day of menstruation is defined for convenience and accuracy as the beginning of a new menstrual cycle. Typically each cycle lasts between 25 and 34 days in 95% of women, with 28 days being the average. Hence the term ‘menstruation’, since it tends to recur at monthly intervals. Total blood loss during each menstruation varies from cycle to cycle, and in different women at different stages of their reproductive life. However, the average blood loss is about 50-60 ml (a teaspoon holds about 5 ml), although it can vary from about 10-80 ml. Excessive loss of blood (menorrhagia) can lead to iron-deficiency anaemia.

Many myths, legends, and taboos have grown up around menstruation throughout the centuries, but all with the underlying sentiment that menstruating women are unclean and capable of producing bad effects on the world about them. It became a focus of religious observance. For example, Hindu women are not supposed to prepare their husbands' food when they are menstruating. Those Moslem women who are normally allowed to pray in a Mosque may not do so during menstruation. Some Buddhists think it is wrong to enter a temple during menstruation and Jews are supposed to refrain from sexual intercourse during this time. In medieval times menstruating women were excluded from going to church and the Church of England has a service for ‘The Churching of Women’, a ceremony to be performed when a woman has had her first menstruation after the birth of a child. And so from the early teaching of Hippocrates, right through the centuries menstruation has been seen as a way of getting rid of something undesirable, unclean and potentially harmful. No wonder such derogatory terms as ‘the curse’ came into existence.

— Saffron Whitehead

Definition

Menstruation is the vaginal bleeding that occurs in adolescent girls and women as a result of hormonal changes. It normally happens in a predictable pattern, once a month.

Description

Menstruation is part of the menstrual cycle, which helps a woman's body prepare for the possibility of pregnancy each month. The parts of the body involved in the menstrual cycle include the uterus and cervix, the ovaries, fallopian tubes, the brain and pituitary gland, and the vagina. Certain body chemicals known as hormones rise and fall during the month, causing the menstrual cycle to occur.

In the first half of the menstrual cycle, estrogen levels rise, causing the lining of the uterus to grow and thicken. This lining is called the endometrium. The two small, grape-shaped organs inside the abdomen on either side of the uterus, known as the ovaries, are filled with hundreds of thousands of eggs and are the organs that allow pregnancy to occur. When a girl reaches puberty, the ovaries respond to a rise in follicle-stimulating hormone and cause one of the eggs to mature. About half way through the menstrual cycle, a surge of luteinizing hormone takes place, and the egg is released. This mature egg is called an ovum, and its release is called ovulation. When the egg is released it travels through one of the two fallopian tubes and down towards the uterus. If the ovum is fertilized by a sperm at this time, pregnancy occurs. However, if a sperm does not fertilize the egg, the body no longer needs the uterine lining to support the fertilized egg. Estrogen and progesterone levels then drop, triggering the uterine lining to gently fall away from the wall of the uterus, and to be shed through the vagina. The discharge of this lining is the menstrual flow. The entire process is called menstruation.

A "normal" menstrual period usually occurs every 28 days, from the first day of a period to the first day of the next. However, this can vary from 22 to 36 days. Each period usually lasts from three to seven days, with the average being five. It may take several years from the start of menstruation for periods to settle into a pattern. Irregular periods are common in early adolescence. Even after adolescence, many factors can throw off the timing of menstruation. These include weight changes, starting a new job or school, and relationship problems.

Menstrual Hygiene Products

Once a girl begins menstruating, she needs to choose from the various menstrual hygiene products which are available. Menstrual hygiene products can be divided into two basic categories: sanitary pads and tampons. Absorbency and a comfortable fit are the main features girls need to look for when purchasing menstrual products. Because a girl's menstrual flow may vary from day to day during the cycle, she may want to use different types of products during her period.

Sanitary pads are worn inside the underwear where they collect the menstrual flow. They come in different sizes, thicknesses, and styles. Some pads have flaps or "wings" that wrap around and attach to the underside of underwear. Others have deodorant and contain perfume. Some girls find that the perfume irritates their skin.

Tampons are the another option for absorbing menstrual flow. Tampons come in various absorbency categories and should be chosen based on the amount of flow experienced. The absorbency of a tampon can be determined by how often it needs to be changed. Girls should use the tampon with the least absorbency necessary to absorb the flow. Tampons should be changed every four to six hours. Tampons also come with a variety of applicators, including plastic and cardboard. Tampons are comfortable to wear and may be a good choice for active girls. They should be inserted carefully to avoid any irritation. A rare, but serious, condition called toxic shock syndrome (TSS) can be connected to tampon use. The higher the absorbency of tampons used, the higher the risk for TSS. To decrease the risk of TSS, girls should choose the lowest absorbency necessary.

Problems With Menstruation

DYSMENORRHEA.Dysmenorrhea is the medical term for menstrual cramps, the dull or throbbing pain in the lower abdomen that many women experience just before and during their menstrual periods. It can be primary or secondary. Primary dysmenorrhea involves no abnormality. Secondary dysmenorrhea involves an underlying physical cause, such as uterine fibroids, pelvic inflammatory disease, or endometriosis. Signs and symptoms of dysmenorrhea, whether it is primary or secondary, may include the following:

• dull, throbbing pain in the lower abdomen
• radiating pain to the lower back and thighs
• nausea, loose stools, sweating, and dizziness (though these are much less common)

If menstrual cramps become severe enough to keep a girl from going about her day-to-day routine, she should see a doctor. The doctor will perform a medical history and physical examination, including a pelvic exam, where he or she will look for any abnormalities, signs of infection, and possible causes of secondary dysmenorrheal. In addition, the doctor may request a variety of diagnostic tests, such as imaging tests, laparoscopy, and hysteroscopy.

Complications can arise from secondary dysmenorrhea. If pelvic inflammatory disease is present, the fallopian tubes may become scarred and possibly cause later infertility or other reproductive problems. Endometriosis can also lead to fertility problems as well.

Many experts believe that prostaglandins, hormone-like substances involved in pain and inflammation and which trigger uterine muscle contractions, are responsible for causing menstrual cramping. Whether the dysmenorrhea is primary or secondary, there are effective ways to treat menstrual pain. Nonsteroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen or naproxen, may block the production of prostaglandins and can be very effective in the treatment of menstrual cramps. In the case of severe cramping, doctors may recommend a low-dose oral contraceptive to prevent ovulation, which may reduce the release of prostaglandins and the severity of the cramps.

DYSFUNCTIONAL UTERINE BLEEDING. Dysfunctional uterine bleeding (DUB) is prolonged or heavy bleeding that often occurs in a menstrual cycle where ovulation did not occur. Heavy bleeding is defined as more than 15 soaked pads or tampons per period, and prolonged bleeding is that which lasts for more than 8 to 10 days. Although DUB is quite common in the first few years after menstruation starts, it can be frightening and should always be reported to a physician. DUB that is accompanied by dizziness and a low blood pressure should be considered a medical emergency. DUB is usually caused by hormonal imbalances. Other causes of bleeding are sexually transmitted disease, an ectopic pregnancy, ovarian cysts, and uterine fibroids or polyps. Young women within the first menstrual period are not usually treated unless symptoms are exceptionally severe or if anemia develops.

Demographics

Girls may start their menstrual period as early as nine years of age and as late as 16 years old. The average age a girl begins menstruating is 12. Girls who are very active in sports or who are quite thin may not develop until a later age. Losing weight while experiencing a growth spurt may also delay menstruation.

In the early 2000s, some people have voiced concern about girls starting their periods at younger and younger ages. However, a study reported in 2003 found that overall, girls in the United States are not beginning menstruation earlier than in the past. Less than 10 percent of girls start their periods before 11 years of age, and 90 percent of all U.S. girls are menstruating by age 14. This age is not significantly different than that reported for girls in 1973. African-American girls on average begin menstruating before Caucasian- and Hispanic-American girls.

Causes and Symptoms

The menstrual cycle takes place each month in response to the hormonal changes which occur when pregnancy does not take place. A number of symptoms can occur just before and during a girl's period which may cause discomfort. These include:

• having pelvic area cramps
• feeling bloated or puffy
• breast tenderness or swelling
• headaches and backaches
• acne breakouts
• mild nausea

These symptoms usually stop or lessen a day or two after the period begins.

Diagnosis

There are several reasons why a girl should see her healthcare provider regarding her menstrual cycle. These include:

• if menstruation has not started by the age of 16
• if a menstrual period lasts for more than seven days
• if periods suddenly stop
• if she is experiencing excessive bleeding
• if she feels suddenly ill while using tampons
• if she bleeds more than a few drops between periods
• if she experiences excessive pain during her period

Treatment

No specific medical treatment is necessary for an uncomplicated menstrual cycle, as it is a normal, healthy process in girls and women.

Alternative Treatment

Some girls may find relief from menstrual discomfort through meditation, yoga, or massage. These stress-relieving activities are unlikely to cause any harm.

Parental Concerns

Though menstruation is no longer the taboo subject it once was, many parents still find that discussing the issue with their daughters can be uncomfortable. This is especially common in families in which the mother is not present. Still, it is important to discuss menstruation with girls when they are preteens, so that they do not experience the potential embarrassment or trauma if they start their first period without knowledge about what is happening to their bodies. Taking the time to prepare may help to make this discussion less awkward.

Resources

Books

Loulan, JoAnn, and Bonnie Worthen. Period: A Girl's Guide to Menstruation. Minnetonka, MN: Book Peddlers, 2001.

Periodicals

Chumlea, William Cameron, et al. "Age at Menarche and Racial Comparisons in U.S. Girls." Pediatrics 111 (January 2003): 110–14.

Organizations

American College of Obstetricians and Gynecologists. 409 12th Street, SW, PO Box 96920, Washington, DC 20090–6290. Web site: www.acog.org.

The Center for Young Women's Health. 300 Longwood Avenue, Box 310, Boston, MA 02115. Web site: www.youngwomenshealth.org.

Web Sites

"Frequently Asked Questions about Menstruation and the Menstrual Cycle." 4woman.gov-The National Women's Health Information Center, November 2002. Available online at www.4woman.gov/faq/menstru.htm (accessed October 25, 2004).

"Period Talk: Preparing Your Preteen for Menstruation." Available online at www.mayoclinic.com/invoke.cfm?id=FL00040 (accessed October 25, 2004).

[Article by: Deanna M. Swartout-Corbeil, RN]

The Bible taught (Leviticus 15: 19-24) that a menstruating woman was not only ‘unclean’ in herself but polluted others. The scientific authority of Pliny's Natural History (AD 77), and many later medical writers, added that she could shrivel plants, kill bees, taint food, and cloud mirrors by her touch, her glance, her breath, or her mere presence—let alone her actual blood. Though many folklore collections avoid this topic, those that do mention it record beliefs and taboos which seem similar everywhere, some of which were still current in the mid-20th century. During her period, a woman must not handle raw meat or go near ham that is being cured, for she will taint it; she must not enter the dairy, or milk will sour and butter-making will fail.

Theologians disagreed on how rigorously to apply to women the Leviticus rule that anyone ‘unclean’ must not approach ‘the tabernacle or any holy thing’; some said they must not even enter a church, but in 579 Pope Gregory instructed missionaries working in England to let them do so, and even receive Communion, since what was natural was not sinful (Bede, Ecclesiastical History, book I, chapter 27). In the 20th century, the debate was still not over; among Primitive Methodists, no menstruating woman could attend a church service (Porter, 1969: 22), and some Catholic girls thought (wrongly) that to take Communion then was a sin [JS].

Other folkloric warnings, current until recently, protected the woman herself from supposed risks. The best known was never to wash your hair or put your feet in cold water, or ‘the blood will fly to your head and send you daft’; this echoes an outdated medical theory about misdirected menstrual blood reaching the brain and causing melancholia. It was also bad to have a bath or go swimming, either because ‘the water will get inside’ or because ‘the water will turn black’. More unusual was the Lincolnshire rule, ‘Don't walk in long grass, the snakes will smell you’ (Sutton, 1992: 31).

The sudden surge of oestrogen which signals the onset of menstruation affects the sebacious glands, making hair greasy, lanky, and unmanageable. Hairdressers avoid styling or tinting a woman's hair at this time, since the results will probably be poor. The current phrase ‘a bad hair day’ for a day when everything goes wrong may be based on the experience that pre-menstrual irritability, clumsiness, and greasy hair coincide [JS].

Sexual intercourse during menstruation was taboo; according to the Bible, it was a crime incurring the death penalty for both parties (Leviticus 20: 18), though secular law has never enforced this. Scripture also warned that ‘menstruous women bring forth monsters’ (II Esdras 5: 8), and medical writers agreed; a popular handbook, Aristotle's Masterpiece (1684, but often reprinted up to 1890), taught that it would probably result in abnormalities such as hairy infants or those with extra limbs (book I, chapter 5). Nowadays, it is occasionally said babies so conceived are red-haired.

Bibliography
The full bibliography list is available here.

• Porter, 1969: 21-3
• Opie and Tatem, 1989: 247
• Sutton, 1992: 16-32
• Patricia Crawford, Past and Present 91 (May 1981), 47-73

The process or the instance of discharging blood and tissue fragments from the uterine wall. Some sportswomen may be particularly susceptible to iron-deficiency anaemia during menstruation because of heavy blood losses combined with the high oxygen demands of their physical activity. Menstruation does not necessarily preclude exceptional athletic performances. World and Olympic titles have been won during all stages of the menstrual cycle. See also menstrual adjustment.

The periodic discharge of the blood-enriched lining of the uterus through the vagina. Menstruation marks the end of one menstrual cycle and the beginning of another.

The shedding of the necrotic mucosa of the endometrium and associated bleeding that occurs in the final phase of the menstrual cycle. The average duration of menstruation is 5 days, in which approximately 30 ml of blood is lost.

• Reproductive System - menstruation: periodic discharge of blood, secretions, and tissue due to shedding of uterine lining when ovum is not fertilized
• Reproduction and Development - menstruation: cyclical shedding of lining of uterus with loss of blood and fluid; menses
• Contraception and Fertility - menstruation: monthly discharge of blood from uterus when conception has not occurred