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Related to menstruation: Menstruation cycle


menstruation, periodic flow of blood and cells from the lining of the uterus in humans and most other primates, occurring about every 28 days in women. Menstruation commences at puberty (usually between age 10 and 17). The onset of menstruation, called menarche, signals the body's coming readiness for childbearing. It continues, unless interrupted by pregnancy until menopause (around age 50).

There have been many myths and taboos associated with menstruation. Some cultures isolated women or thought the menstrual flow “unclean” or a “curse.” More recent taboos against exercise or sexual intercourse during menstruation are slowly lifting. Some scientists have asked why menstruation occurs at all—why the uterine lining does not remain in place, regenerating itself as other parts of the body (such as the skin and digestive tract) do. One theory is that menstruation is a defense against microbes that enter the uterus with incoming sperm.

The Menstrual Cycle

In the first phase of each cycle, the lining, or endometrium, of the uterus undergoes rapid proliferation of cells and venous channels in preparation for pregnancy. Midway through the cycle an ovum (egg) is released from an ovary. If, while passing through the fallopian tube the ovum is fertilized by a sperm, implantation in the uterus occurs and the thickened lining helps support the pregnancy. When the ovum is not fertilized, this tissue and blood are shed. The proliferation of the uterine wall then begins once more in expectation of the next release of an ovum, and if conception does not take place, it sloughs off again. The process continues monthly until pregnancy occurs or until ovulation ceases at menopause.

The natural rhythm of the menstrual cycle may be broken or temporarily halted by hormonal imbalance, malnutrition, illness, or emotional disturbance (see amenorrhea). Menstruation is controlled by the hypothalamus and the pituitary gland and hormones, such as estrogen, which prepares the lining of the uterus, and progesterone, which helps maintain a pregnancy.

Dysmenorrhea and Premenstrual Syndrome

Many women experience painful menstruation, or dysmenorrhea. The uterine contractions that result in the cramps experienced by these women appear to be caused by hormones called prostaglandins that are produced in the second half of the cycle. Oral contraceptives and other drugs that reduce the production of prostaglandins are sometimes used in treatment. Other women experience symptoms such as behavioral changes, breast tenderness, and fatigue during the week immediately preceding menstruation, a condition referred to as premenstrual syndrome, or PMS.


See publications of the National Institute of Child Health and Human Development; Boston Women's Health Book Collective, Our Bodies, Ourselves for the New Century (1998).

The Columbia Electronic Encyclopedia™ Copyright © 2022, Columbia University Press. Licensed from Columbia University Press. All rights reserved.


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.

McGraw-Hill Concise Encyclopedia of Bioscience. © 2002 by The McGraw-Hill Companies, Inc.


The periodic discharge of sanguineous fluid and sloughing of the uterine lining in women from puberty to the menopause. Also known as menses.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


the approximately monthly discharge of blood and cellular debris from the uterus by nonpregnant women from puberty to the menopause
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005


It is a common dream for women and its interpretation is mostly positive. Dreaming about having your menses can be symbolic of releasing tension and worry. Women are often concerned about their reproductive system. (i. e., pregnancy, sexual relationships or their body’s “time clock” ). Parallel to the menstrual cycle there is a monthly emotional cycle that most women are aware of and experience. During the time of menstruation there is a release of anxiety and an attainment of emotional balance. As a dream symbol it suggests that some difficult times may be over for you and that you can relax. On occasion this dream suggests a loss of energy and disappointment.
Bedside Dream Dictionary by Silvana Amar Copyright © 2007 by Skyhorse Publishing, Inc.
References in periodicals archive ?
Menstruation is a public health issue that has remained hidden for far too long.
Table-III: The Relationship between the Hemoglobin and Ferritin Levels, SF-36 QoLS Subdimensions, Components of the BFI, and Menstruation Duration.
RTIs have become a major public health concern, but the percentage of the burden being imposed by such infections, assigned to inadequate hygienic management of menstruation, is not known.
Regular menses occurred in 65.5 % (n = 131/200) of girls; a cycle length ranging from 21 to 35 days (Mean, 27.58 [+ or -] 1.79 days) and the mean duration of menstruation was 4.77 [+ or -]1.06 days with a range of 2-8 days.
Usually, during menstruation and pubescence, most of adolescent girls have lack of knowledge and hygienic practice.
Only 48.50% of girls were aware that secondary sexual characters and menstruation are part of physiological development.
Issues associated with menstruation are never discussed openly, and this burdens young girls by keeping them ignorant of their biological functions.
There are many young girls who do not know what their period is until Kerry Tinga THE KERRY DIARIES they experience it because of the stigma on discussing menstruation. As progressive as my school's take was to educate the young girls of my class, it was still taught separately from the boys, which arguably entrenches the shame mentality about discussing menstruation.
The 26-minute film shows them take on prejudice and stereotypes associated with menstruation in India.
KARACHI -- Even in this era of fast-growing use of technology and flow of information, in many families start of menstruation cycle at a young age is considered an ailment.
KARACHI -- Even in this era of fast growing use of technology and flow of information, in many families start of menstruation cycle at young age is considered an ailment.
Primary school pupils will be told that "trans boys and men and non-binary people may have periods" in a bid to tackle stigma surrounding menstruation.