Menstruation
Encyclopedia
Menstruation is the shedding of the uterine lining (endometrium
). It occurs on a regular basis in sexually reproductive-age females of certain mammal
species. This article focuses on human menstruation.
The average blood loss during a monthly menstrual period is 35 milliliters (or 4 to 6 tablespoons of menstrual fluid) with 10-80 milliliters considered typical. Menstrual fluid is the correct name for the menstrual flow, although many people refer to it as menstrual blood. Menstrual fluid in fact contains some blood, as well as cervical mucus, vaginal secretions, and endometrial tissue. Menstrual fluid is reddish-brown, a slightly darker colour than blood.
Many women also notice shedding of the uterus's endometrium
lining during menstruation. The shed endometrium lining appears as small pieces of tissue mixed with the blood. These pieces of tissue are often called menstrual clots (although they are pieces of the endometrium, and are not true blood clots) and are common; they more frequently occur in women who experience a heavier-than-average menstrual flow. Sometimes this is incorrectly thought to indicate an early-term miscarriage of an embryo. An enzyme
called plasmin
— contained in the endometrium — tends to inhibit the blood from clotting. Because of this blood loss, premenopausal women have higher dietary requirements for iron
to prevent iron deficiency
.
The first experience of a menstrual period during puberty is called menarche
. Menarche typically occurs between ages 10 and 17. Perimenopause is when fertility in a woman declines, and menstruation may occur infrequently in the years leading up to menopause
, when a woman stops menstruating completely and is no longer fertile. Menopause
typically occurs between the late 40s and 50s in Western countries.
, and by muscle contractions (menstrual cramping) involving the uterus that can precede or accompany menstruation. Women may notice water retention, changes in sex drive, fatigue, breast tenderness, or nausea. Breast
swelling and discomfort may be caused by premenstrual water retention
. Binge eating
occurs in a minority of menstruating women. Usually, such sensations are mild, and some women notice very few physical changes associated with menstruation. A healthy diet, reduced consumption of salt, caffeine and alcohol, and regular exercise are often effective in controlling these physical changes. Typical physical changes related to menstruation are not ordinarily considered to be true Premenstrual Syndrome. However, it is common for non-medical people to refer to these physical changes colloquially as "PMS symptoms". The sensations experienced vary from woman to woman and from cycle to cycle.
cramps during menstruation. The muscles of the uterus, and abdominal muscles surrounding the uterus, contract spasmodically to push the menstrual fluid out of the uterus. The contractions are produced by the tissue lining the uterus, which is believed to release an excess of fatty acids called prostaglandins that stimulate the muscles, leading to contractions. This is called primary dysmenorrhea. Primary dysmenorrhea usually begins within a year or two of menarche
. It may continue until menopause
, but many women find that symptoms of dysmenorrhea gradually subside after their mid-20s. If the pain occurs between menstrual periods, or lasts longer than the first few days of the period, it is called secondary dysmenorrhea.
Symptoms of dysmenorrhea may become debilitating in some women. It is unknown why this occurs in some women and not others. Severe symptoms may include pain spreading to hips, lower back and thighs, nausea and frequent diarrhea or constipation. Treatments target excess prostaglandin, using anti-prostaglandin medications or oral contraceptives. Nonsteroidal antiinflammatory drugs (NSAIDS), such as over-the-counter ibuprofen
and naproxen
, may ease symptoms.
is associated with pregnancy. The prevalence of PMS is estimated to be between 3% and 30%. More severe symptoms of anxiety or depression may be signs of Premenstrual Syndrome. Rarely, in individuals susceptible to psychotic episodes, menstruation may be a trigger (menstrual psychosis
).
(dysmenorrhea
), migraine
headaches, and severe depression
. Dysmenorrhea
, or severe uterine pain, is particularly common for adolescents and young women (one study found that 67.2% of girls aged 13–19 suffer from it). This phenomenon is called Premenstrual Syndrome. More severe symptoms may be classified as Premenstrual Dysphoric Disorder
(PMDD).
Dysfunctional uterine bleeding
is a hormonally caused bleeding abnormality. Dysfunctional uterine bleeding typically occurs in premenopausal women who do not ovulate normally (i.e. are anovulatory). All these bleeding abnormalities need medical attention; they may indicate hormone imbalances, uterine fibroids, or other problems. As pregnant patients may bleed, a pregnancy test
forms part of the evaluation of abnormal bleeding.
, and corresponds closely with the hormonal cycle, and is therefore used as the limit between cycles; Menstrual cycles are counted from the first day of menstrual bleeding, a point in time commonly termed last menstrual period (LMP). The time from LMP until ovulation is, on average, 14.6 days, but with substantial variation both between women and between cycles in any single woman, with an overall 95% prediction interval
of 8.2 to 20.5 days.
During pregnancy
and for some time after childbirth
, menstruation is normally suspended; this state is known as amenorrhoea
, i.e. absence of the menstrual cycle. If menstruation has not resumed, fertility is low during lactation
. The average length of postpartum amenorrhoea is longer when certain breastfeeding
practices are followed; this may be done intentionally as birth control
.
, often simply called 'the pill'. They are most often combined hormone pills containing estrogen
and are taken in 28 day cycles, 21 hormonal pills with either a 7 day break from pills, or 7 placebo pills during which the woman menstruates. Hormonal contraception
acts by using low doses of hormones to prevent ovulation, and thus prevent conception in sexually active women. But by using placebo pills for a 7-day span during the month, a regular menstrual period is still experienced.
Injections such as depo-provera became available in the 1960s. Progestogen implants such as Norplant
in the 1980s and extended cycle combined oral contraceptive pills in the early 2000s.
Using synthetic hormones, it is possible for a woman to completely eliminate menstrual periods. When using progestogen implants, menstruation may be reduced to 3 or 4 menstrual periods per year. By taking progestogen-only contraceptive pills (sometimes called the 'mini-pill') continuously without a 7-day span of using placebo pills, the menstrual period is eliminated entirely. Some women do this simply for convenience in the short-term, while others prefer to eliminate periods altogether when possible.
Reusable items:
Disposable items:
In addition to products to contain the menstrual flow, pharmaceutical companies likewise provide products — commonly non-steroidal anti-inflammatory drug
s (NSAIDs) — to relieve menstrual cramps. Some herbs, such as dong quai, raspberry
leaf and crampbark, are also claimed to relieve menstrual pain; however there is no documented scientific evidence to prove this.
in Judaism and the ghusl
in Islam). Some traditional societies sequester females in residences, "menstrual huts", that are reserved for that exclusive purpose until the end of their menstrual period.
have a uterine lining that builds up when the animal is fertile, but is dismantled (menstruated) when the animal is infertile. Some anthropologists have questioned the energy cost of rebuilding the endometrium
every fertility cycle. However, anthropologist Beverly Strassmann has proposed that the energy savings of not having to continuously maintain the uterine lining more than offsets energy cost of having to rebuild the lining in the next fertility cycle, even in species such as humans where much of the lining is lost through bleeding (overt menstruation) rather than reabsorbed (covert menstruation). However, even in humans, much of it is re-absorbed.
Many have questioned the evolution of overt menstruation in humans and related species, speculating on what advantage there could be to losing blood associated with dismantling the endometrium rather than absorbing it, as most mammals do.
Beginning in 1971, some research suggested that menstrual cycles of co-habiting human females became synchronized. A few anthropologists hypothesized that in hunter-gatherer societies, males would go on hunting journeys whilst the females of the tribe were menstruating, speculating that the females would not have been as receptive to sexual relations while menstruating. However, there is currently significant dispute as to whether menstrual synchrony
exists.
Humans do, in fact, reabsorb about two-thirds of the endometrium each cycle. Strassmann asserts that overt menstruation occurs not because it is beneficial in itself. Rather, the fetal development of these species requires a more developed endometrium, one which is too thick to reabsorb completely. Strassman correlates species that have overt menstruation to those that have a large uterus relative to the adult female body size.
Endometrium
-Function:The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity. During the menstrual cycle or estrous cycle, the endometrium grows to a...
). It occurs on a regular basis in sexually reproductive-age females of certain mammal
Mammal
Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...
species. This article focuses on human menstruation.
Overview
Regular menstruation (also called eumenorrhea) lasts for a few days, usually 3 to 5 days, but anywhere from 2 to 8 days is considered normal. The average menstrual cycle is 28 days long from the first day of one menstrual period to the first day of the next. A normal menstrual cycle is typically between 21 and 35 days between menstrual periods.The average blood loss during a monthly menstrual period is 35 milliliters (or 4 to 6 tablespoons of menstrual fluid) with 10-80 milliliters considered typical. Menstrual fluid is the correct name for the menstrual flow, although many people refer to it as menstrual blood. Menstrual fluid in fact contains some blood, as well as cervical mucus, vaginal secretions, and endometrial tissue. Menstrual fluid is reddish-brown, a slightly darker colour than blood.
Many women also notice shedding of the uterus's endometrium
Endometrium
-Function:The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity. During the menstrual cycle or estrous cycle, the endometrium grows to a...
lining during menstruation. The shed endometrium lining appears as small pieces of tissue mixed with the blood. These pieces of tissue are often called menstrual clots (although they are pieces of the endometrium, and are not true blood clots) and are common; they more frequently occur in women who experience a heavier-than-average menstrual flow. Sometimes this is incorrectly thought to indicate an early-term miscarriage of an embryo. An enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
called plasmin
Plasmin
Plasmin is an important enzyme present in blood that degrades many blood plasma proteins, most notably, fibrin clots. The degradation of fibrin is termed fibrinolysis. In humans, the plasmin protein is encoded by the PLG gene.- Function :...
— contained in the endometrium — tends to inhibit the blood from clotting. Because of this blood loss, premenopausal women have higher dietary requirements for iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
to prevent iron deficiency
Iron deficiency (medicine)
Iron deficiency is one of the most common of the nutritional deficiencies. Iron is present in all cells in the human body, and has several vital functions...
.
The first experience of a menstrual period during puberty is called menarche
Menarche
Menarche is the first menstrual cycle, or first menstrual bleeding, in female human beings. From both social and medical perspectives it is often considered the central event of female puberty, as it signals the possibility of fertility....
. Menarche typically occurs between ages 10 and 17. Perimenopause is when fertility in a woman declines, and menstruation may occur infrequently in the years leading up to menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
, when a woman stops menstruating completely and is no longer fertile. Menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
typically occurs between the late 40s and 50s in Western countries.
Physical experience
In most women, various physical changes are brought about by natural fluctuations in hormone levels during the menstrual cycleMenstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
, and by muscle contractions (menstrual cramping) involving the uterus that can precede or accompany menstruation. Women may notice water retention, changes in sex drive, fatigue, breast tenderness, or nausea. Breast
Breast
The breast is the upper ventral region of the torso of a primate, in left and right sides, which in a female contains the mammary gland that secretes milk used to feed infants.Both men and women develop breasts from the same embryological tissues...
swelling and discomfort may be caused by premenstrual water retention
Premenstrual water retention
Premenstrual water retention is a common phenomenon associated with the menstrual cycle. Water retention is most noticeable for its temporary, but uncomfortable, enlargement of the breasts. The excess fluid is lost during menstruation...
. Binge eating
Binge eating
Binge eating is a pattern of disordered eating which consists of episodes of uncontrollable eating. It is sometimes as a symptom of binge eating disorder. During such binges, a person rapidly consumes an excessive amount of food...
occurs in a minority of menstruating women. Usually, such sensations are mild, and some women notice very few physical changes associated with menstruation. A healthy diet, reduced consumption of salt, caffeine and alcohol, and regular exercise are often effective in controlling these physical changes. Typical physical changes related to menstruation are not ordinarily considered to be true Premenstrual Syndrome. However, it is common for non-medical people to refer to these physical changes colloquially as "PMS symptoms". The sensations experienced vary from woman to woman and from cycle to cycle.
Painful menstrual cramps
Many women experience painful uterineUterus
The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...
cramps during menstruation. The muscles of the uterus, and abdominal muscles surrounding the uterus, contract spasmodically to push the menstrual fluid out of the uterus. The contractions are produced by the tissue lining the uterus, which is believed to release an excess of fatty acids called prostaglandins that stimulate the muscles, leading to contractions. This is called primary dysmenorrhea. Primary dysmenorrhea usually begins within a year or two of menarche
Menarche
Menarche is the first menstrual cycle, or first menstrual bleeding, in female human beings. From both social and medical perspectives it is often considered the central event of female puberty, as it signals the possibility of fertility....
. It may continue until menopause
Menopause
Menopause is a term used to describe the permanent cessation of the primary functions of the human ovaries: the ripening and release of ova and the release of hormones that cause both the creation of the uterine lining and the subsequent shedding of the uterine lining...
, but many women find that symptoms of dysmenorrhea gradually subside after their mid-20s. If the pain occurs between menstrual periods, or lasts longer than the first few days of the period, it is called secondary dysmenorrhea.
Symptoms of dysmenorrhea may become debilitating in some women. It is unknown why this occurs in some women and not others. Severe symptoms may include pain spreading to hips, lower back and thighs, nausea and frequent diarrhea or constipation. Treatments target excess prostaglandin, using anti-prostaglandin medications or oral contraceptives. Nonsteroidal antiinflammatory drugs (NSAIDS), such as over-the-counter ibuprofen
Ibuprofen
Ibuprofen is a nonsteroidal anti-inflammatory drug used for relief of symptoms of arthritis, fever, as an analgesic , especially where there is an inflammatory component, and dysmenorrhea....
and naproxen
Naproxen
Naproxen sodium is a nonsteroidal anti-inflammatory drug commonly used for the reduction of pain, fever, inflammation and stiffness caused by conditions such as:...
, may ease symptoms.
Emotional and psychological experience
Some women experience emotional disturbances associated with menstruation. These range from the irritability, to tiredness, or "weepiness" (i.e. easily-provoked tearfulness). A similar range of emotional effects and mood swingsMood Swings
Mood Swings is an album by Koby Israelite released in 2005 on Tzadik.- Track listing :# "Dror Ikra" - 3:03# "Return of the Idiots" - 2:19# "It Is Not a War Here" - 7:05# "Ethnometalogy" - 5:08# "Europa?" - 2:49# "Hiriya On My Mind" - 4:53...
is associated with pregnancy. The prevalence of PMS is estimated to be between 3% and 30%. More severe symptoms of anxiety or depression may be signs of Premenstrual Syndrome. Rarely, in individuals susceptible to psychotic episodes, menstruation may be a trigger (menstrual psychosis
Menstrual psychosis
-Definition:This is a comparatively uncommon form of severe mental illness, with the following characteristics:*Abrupt onset against a background of normality.*Brief duration, with full recovery....
).
Premenstrual Syndrome
In some cases, stronger physical and emotional or psychological sensations may become debilitating, and include significant menstrual painPain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
(dysmenorrhea
Dysmenorrhea
Dysmenorrhea is a gynecological medical condition of pain during menstruation that interferes with daily activities, as defined by ACOG and others. Still, dysmenorrhea is often defined simply as menstrual pain, or at least menstrual pain that is excessive...
), migraine
Migraine
Migraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...
headaches, and severe depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
. Dysmenorrhea
Dysmenorrhea
Dysmenorrhea is a gynecological medical condition of pain during menstruation that interferes with daily activities, as defined by ACOG and others. Still, dysmenorrhea is often defined simply as menstrual pain, or at least menstrual pain that is excessive...
, or severe uterine pain, is particularly common for adolescents and young women (one study found that 67.2% of girls aged 13–19 suffer from it). This phenomenon is called Premenstrual Syndrome. More severe symptoms may be classified as Premenstrual Dysphoric Disorder
Premenstrual dysphoric disorder
Premenstrual dysphoric disorder is a severe form of premenstrual syndrome, afflicting 3% to 8% of women. It is a diagnosis associated primarily with the luteal phase of the menstrual cycle...
(PMDD).
Menstrual disorders
It should be noted that there is a wide spectrum of differences between how women may experience menstruation. What may indicate a more serious physical problem for one woman, may be quite normal for another. There are several ways that a woman's menstrual cycle can differ from the norm, any of which should be discussed with a doctor to identify the underlying cause:| Symptom | See article |
|---|---|
| Infrequent periods | Oligomenorrhea Oligomenorrhea Oligomenorrhea is infrequent menstruation. More strictly, it is menstrual periods occurring at intervals of greater than 35 days, with only four to nine periods in a year. Also, menstrual periods should have been regularly established previously before the development of infrequent flow... |
| Short or extremely light periods | Hypomenorrhea Hypomenorrhea Hypomenorrhea or hypomenorrhoea, also known as short or scanty periods, is extremely light menstrual blood flow. It is the opposite of hypermenorrhea which is more properly called menorrhagia.-Overview:... |
| Too-frequent periods (defined as more frequently than every 21 days) | Polymenorrhea |
| Extremely heavy or long periods (one guideline is soaking a sanitary napkin or tampon every hour or so, or menstruating for longer than 7 days) | Hypermenorrhea |
| Extremely painful periods | Dysmenorrhea Dysmenorrhea Dysmenorrhea is a gynecological medical condition of pain during menstruation that interferes with daily activities, as defined by ACOG and others. Still, dysmenorrhea is often defined simply as menstrual pain, or at least menstrual pain that is excessive... |
| Breakthrough bleeding (also called spotting) between periods; normal in many women | Metrorrhagia Metrorrhagia Metrorrhagia, also known as breakthrough bleeding or spotting, is uterine bleeding at irregular intervals, particularly between the expected menstrual periods.In some women, menstrual spotting between periods occurs as a normal and harmless part of ovulation... |
| Absent periods | Amenorrhea |
Dysfunctional uterine bleeding
Dysfunctional uterine bleeding
Dysfunctional Uterine Bleeding is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable structural or organic pathology.usually due to hormonal disturbances....
is a hormonally caused bleeding abnormality. Dysfunctional uterine bleeding typically occurs in premenopausal women who do not ovulate normally (i.e. are anovulatory). All these bleeding abnormalities need medical attention; they may indicate hormone imbalances, uterine fibroids, or other problems. As pregnant patients may bleed, a pregnancy test
Pregnancy test
A pregnancy test attempts to determine whether or not a woman is pregnant.These markers are found in urine and blood, and pregnancy tests require sampling one of these substances. The first of these markers to be discovered, human chorionic gonadotropin , was discovered in 1930 to be produced by...
forms part of the evaluation of abnormal bleeding.
Menstruation and pregnancy
Menstruation is the most visible phase of the menstrual cycleMenstrual cycle
The menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
, and corresponds closely with the hormonal cycle, and is therefore used as the limit between cycles; Menstrual cycles are counted from the first day of menstrual bleeding, a point in time commonly termed last menstrual period (LMP). The time from LMP until ovulation is, on average, 14.6 days, but with substantial variation both between women and between cycles in any single woman, with an overall 95% prediction interval
Prediction interval
In statistical inference, specifically predictive inference, a prediction interval is an estimate of an interval in which future observations will fall, with a certain probability, given what has already been observed...
of 8.2 to 20.5 days.
During pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
and for some time after childbirth
Childbirth
Childbirth is the culmination of a human pregnancy or gestation period with the birth of one or more newborn infants from a woman's uterus...
, menstruation is normally suspended; this state is known as amenorrhoea
Amenorrhoea
Amenorrhoea , amenorrhea , or amenorrhœa, is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen during pregnancy and lactation , the latter also forming the basis of a form of contraception known as the lactational amenorrhoea method...
, i.e. absence of the menstrual cycle. If menstruation has not resumed, fertility is low during lactation
Lactation
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process occurs in all female mammals, however it predates mammals. In humans the process of feeding milk is called breastfeeding or nursing...
. The average length of postpartum amenorrhoea is longer when certain breastfeeding
Breastfeeding
Breastfeeding is the feeding of an infant or young child with breast milk directly from female human breasts rather than from a baby bottle or other container. Babies have a sucking reflex that enables them to suck and swallow milk. It is recommended that mothers breastfeed for six months or...
practices are followed; this may be done intentionally as birth control
Birth control
Birth control is an umbrella term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception , contragestion and abortion...
.
Use of synthetic hormones to control menstruation
Since the late 1960s, many women have chosen to control the frequency of menstruation with long-acting hormonal birth controlHormonal contraception
Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive...
, often simply called 'the pill'. They are most often combined hormone pills containing estrogen
Estrogen
Estrogens , oestrogens , or œstrogens, are a group of compounds named for their importance in the estrous cycle of humans and other animals. They are the primary female sex hormones. Natural estrogens are steroid hormones, while some synthetic ones are non-steroidal...
and are taken in 28 day cycles, 21 hormonal pills with either a 7 day break from pills, or 7 placebo pills during which the woman menstruates. Hormonal contraception
Hormonal contraception
Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method—the combined oral contraceptive...
acts by using low doses of hormones to prevent ovulation, and thus prevent conception in sexually active women. But by using placebo pills for a 7-day span during the month, a regular menstrual period is still experienced.
Injections such as depo-provera became available in the 1960s. Progestogen implants such as Norplant
Norplant
Norplant is a form of birth control developed by the Population Council that was first approved in 1983 in Finland, where it was manufactured by Leiras Oy Pharmaceuticals...
in the 1980s and extended cycle combined oral contraceptive pills in the early 2000s.
Using synthetic hormones, it is possible for a woman to completely eliminate menstrual periods. When using progestogen implants, menstruation may be reduced to 3 or 4 menstrual periods per year. By taking progestogen-only contraceptive pills (sometimes called the 'mini-pill') continuously without a 7-day span of using placebo pills, the menstrual period is eliminated entirely. Some women do this simply for convenience in the short-term, while others prefer to eliminate periods altogether when possible.
Menstrual suppression
Some women use hormonal contraception in this way to eliminate periods for months or years at a time, a practise called menstrual suppression. When the first birth control pill was being developed, the researchers were aware that they could use the contraceptive to space menstrual periods up to 90 days apart, but they settled on a 28-day cycle that would mimic a natural menstrual cycle and produce monthly periods. The intention behind this decision was the hope of the inventor, John Rock, to win approval for his invention from the Roman Catholic Church. That attempt failed, but the 28-day cycle remained the standard when the pill became available to the public. There is debate among medical researchers about the potential long-term impacts of these practises upon women's health. Some researchers point to the fact that historically, women have had far fewer menstrual periods throughout their lifetimes, a result of shorter life expectancies, as well as a greater length of time spent pregnant or breast-feeding, which reduced the number of periods experienced by women. These researchers believe that the higher number of menstrual periods experienced by women in modern societies may have a negative impact upon women's health. On the other hand, some researchers believe there is a greater potential for negative impacts from exposing women perhaps unnecessarily to regular low doses of synthetic hormones over their reproductive years.Menstrual products
Most women use something to absorb or catch their menses. There are a number of different methods available.Reusable items:
- Reusable cloth padsCloth menstrual padCloth menstrual pads are a reusable alternative to disposable sanitary napkins.They receive praise for being environmentally friendly, cost-cutting, as well as having purported health benefits....
— Pads that are made of cotton (often organicOrganic farmingOrganic farming is the form of agriculture that relies on techniques such as crop rotation, green manure, compost and biological pest control to maintain soil productivity and control pests on a farm...
), terryclothTerryclothThere are two types of terry fabrics# Towell Terry is a [woven] fabric with long loops that can absorb large amounts of water. Its content is usually 100% cotton, but may sometimes contain polyester....
, or flannelFlannelFlannel is a soft woven fabric, of various fineness. Flannel was originally made from carded wool or worsted yarn, but is now often made from either wool, cotton, or synthetic fibre. Flannel may be brushed to create extra softness or remain unbrushed. The brushing process is a mechanical process...
, and may be handsewn (from material or reused old clothes and towels) or storebought. - Menstrual cupMenstrual cupA menstrual cup is a type of cup or barrier worn inside the vagina during menstruation to collect menstrual fluid. Unlike tampons and pads, the cup collects menstrual fluid rather than absorbing it...
s — A firm, flexible bell-shaped device worn inside the vagina to catch menstrual flow. Reusable versions include rubber or silicone cups. Sterilised after each period. - Sea spongeSea spongeSponges are animals of the phylum Porifera . Their bodies consist of jelly-like mesohyl sandwiched between two thin layers of cells. While all animals have unspecialized cells that can transform into specialized cells, sponges are unique in having some specialized cells, but can also have...
s — Natural sponges, worn internally like a tampon to absorb menstrual flow. - Padded panties — Reusable cloth (usually cotton) underwearUndergarmentUndergarments or underwear are clothes worn under other clothes, often next to the skin. They keep outer garments from being soiled by bodily secretions and discharges, shape the body, and provide support for parts of it. In cold weather, long underwear is sometimes worn to provide additional...
with extra absorbent layers sewn in to absorb flow. - BlanketBlanketA blanket is a type of bedding, generally speaking, a large piece of cloth, intended to keep the user warm, especially while sleeping. Blankets are distinguished from sheets by their thickness and purpose; the thickest sheet is still thinner than the lightest blanket. Blankets are generally used...
, towelTowelA towel is a piece of absorbent fabric or paper used for drying or wiping. It draws moisture through direct contact, often using a blotting or a rubbing motion. Common household textile towels are made from cotton, rayon, bamboo, nonwoven fibers or a few other materials.-Types of towels:* A bath...
— (also known as a draw sheet) — large reusable piece of cloth, most often used at night, placed between legs to absorb menstrual flow.
Disposable items:
- Sanitary napkinSanitary napkinA sanitary napkin, sanitary towel, sanitary pad, menstrual pad, maxi pad, or pad is an absorbent item worn by a woman while she is menstruating, recovering from vaginal surgery, for lochia , abortion, or any other situation where it is necessary to absorb a flow of blood from a woman's vagina.These...
s (Sanitary towels) or pads — Somewhat rectangular pieces of material worn in the underwear to absorb menstrual flow, often with "wings," pieces that fold around the undergarment and/or an adhesive backing to hold the pad in place. Disposable pads may contain wood pulpWood pulpPulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fibre crops or waste paper. Wood pulp is the most common raw material in papermaking.-History:...
or gelGelA gel is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state...
products, usually with a plastic lining and bleached. Some sanitary napkins, particularly older styles, are held in place by a belt-like apparatus, instead of adhesive or wings. - TamponTamponA tampon is a mass of cotton or rayon or a mixture of the two inserted into a body cavity or wound to absorb bodilyfluid. The most common type in daily use is designed to be inserted into the vagina during menstruation to absorb the flow of menstrual fluid...
s — Disposable cylinders of treated rayonRayonRayon is a manufactured regenerated cellulose fiber. Because it is produced from naturally occurring polymers, it is neither a truly synthetic fiber nor a natural fiber; it is a semi-synthetic or artificial fiber. Rayon is known by the names viscose rayon and art silk in the textile industry...
/cottonCottonCotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
blends or all-cotton fleece, usually bleached, that are inserted into the vagina to absorb menstrual flow. - Padettes — Disposable wads of treated rayon/cotton blend fleece that are placed within the inner labia to absorb menstrual flow.
- Disposable menstrual cups — A firm, flexible cup-shaped device worn inside the vagina to catch menstrual flow. Disposable cups are made of soft plastic.
In addition to products to contain the menstrual flow, pharmaceutical companies likewise provide products — commonly non-steroidal anti-inflammatory drug
Non-steroidal anti-inflammatory drug
Nonsteroidal anti-inflammatory drugs, usually abbreviated to NSAIDs or NAIDs, but also referred to as nonsteroidal anti-inflammatory agents/analgesics or nonsteroidal Anti-inflammatory medicines , are drugs with analgesic and antipyretic effects and which have, in higher doses, anti-inflammatory...
s (NSAIDs) — to relieve menstrual cramps. Some herbs, such as dong quai, raspberry
Raspberry
The raspberry or hindberry is the edible fruit of a multitude of plant species in the genus Rubus, most of which are in the subgenus Idaeobatus; the name also applies to these plants themselves...
leaf and crampbark, are also claimed to relieve menstrual pain; however there is no documented scientific evidence to prove this.
Culture and menstruation
Many religions have menstruation-related traditions. These may be bans on certain actions during menstruation (such as intercourse in orthodox Judaism and Islam), or rituals to be performed at the end of each menses (such as the mikvahMikvah
Mikveh is a bath used for the purpose of ritual immersion in Judaism...
in Judaism and the ghusl
Ghusl
Ghusl is an Arabic term referring to the full ablution required in Islam for various rituals and prayers. The ablution becomes mandatory for any adult Muslim after having sexual intercourse, any sexual discharge , completion of the menstrual cycle, giving birth, and death by natural causes.Islam...
in Islam). Some traditional societies sequester females in residences, "menstrual huts", that are reserved for that exclusive purpose until the end of their menstrual period.
Evolution
All female placental mammalsEutheria
Eutheria is a group of mammals consisting of placental mammals plus all extinct mammals that are more closely related to living placentals than to living marsupials . They are distinguished from noneutherians by various features of the feet, ankles, jaws and teeth...
have a uterine lining that builds up when the animal is fertile, but is dismantled (menstruated) when the animal is infertile. Some anthropologists have questioned the energy cost of rebuilding the endometrium
Endometrium
-Function:The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity. During the menstrual cycle or estrous cycle, the endometrium grows to a...
every fertility cycle. However, anthropologist Beverly Strassmann has proposed that the energy savings of not having to continuously maintain the uterine lining more than offsets energy cost of having to rebuild the lining in the next fertility cycle, even in species such as humans where much of the lining is lost through bleeding (overt menstruation) rather than reabsorbed (covert menstruation). However, even in humans, much of it is re-absorbed.
Many have questioned the evolution of overt menstruation in humans and related species, speculating on what advantage there could be to losing blood associated with dismantling the endometrium rather than absorbing it, as most mammals do.
Beginning in 1971, some research suggested that menstrual cycles of co-habiting human females became synchronized. A few anthropologists hypothesized that in hunter-gatherer societies, males would go on hunting journeys whilst the females of the tribe were menstruating, speculating that the females would not have been as receptive to sexual relations while menstruating. However, there is currently significant dispute as to whether menstrual synchrony
McClintock effect
Menstrual synchrony is a phenomenon reported in 1971 wherein the menstrual cycles of women who lived together reportedly became synchronized over time...
exists.
Humans do, in fact, reabsorb about two-thirds of the endometrium each cycle. Strassmann asserts that overt menstruation occurs not because it is beneficial in itself. Rather, the fetal development of these species requires a more developed endometrium, one which is too thick to reabsorb completely. Strassman correlates species that have overt menstruation to those that have a large uterus relative to the adult female body size.
See also
- EndometriumEndometrium-Function:The endometrium is the innermost glandular layer and functions as a lining for the uterus, preventing adhesions between the opposed walls of the myometrium, thereby maintaining the patency of the uterine cavity. During the menstrual cycle or estrous cycle, the endometrium grows to a...
- Menses
- Menstrual cycleMenstrual cycleThe menstrual cycle is the scientific term for the physiological changes that can occur in fertile women for the purpose of sexual reproduction. This article focuses on the human menstrual cycle....
- OvaryOvaryThe ovary is an ovum-producing reproductive organ, often found in pairs as part of the vertebrate female reproductive system. Ovaries in anatomically female individuals are analogous to testes in anatomically male individuals, in that they are both gonads and endocrine glands.-Human anatomy:Ovaries...
- OvulationOvulationOvulation is the process in a female's menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum . Ovulation also occurs in the estrous cycle of other female mammals, which differs in many fundamental ways from the menstrual cycle...
- Sanitary napkinSanitary napkinA sanitary napkin, sanitary towel, sanitary pad, menstrual pad, maxi pad, or pad is an absorbent item worn by a woman while she is menstruating, recovering from vaginal surgery, for lochia , abortion, or any other situation where it is necessary to absorb a flow of blood from a woman's vagina.These...
- Menstrual cupMenstrual cupA menstrual cup is a type of cup or barrier worn inside the vagina during menstruation to collect menstrual fluid. Unlike tampons and pads, the cup collects menstrual fluid rather than absorbing it...
- TamponTamponA tampon is a mass of cotton or rayon or a mixture of the two inserted into a body cavity or wound to absorb bodilyfluid. The most common type in daily use is designed to be inserted into the vagina during menstruation to absorb the flow of menstrual fluid...
- UterusUterusThe uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...