Menstruation
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Menstruation is a woman's monthly bleeding. It is also called
menses, menstrual period, or period. When a woman has her period, she
is menstruating. The menstrual blood is partly blood and partly tissue from the
inside of the uterus (womb). It flows from the uterus through the small
opening in the cervix, and passes out of the body through the
vagina. Most menstrual periods last from three to five days.
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Menstruation is part of the menstrual cycle, which helps a woman's body
prepare for the possibility of pregnancy each month. A cycle starts on the first
day of a period. The average menstrual cycle is 28 days long. However, a cycle
can range anywhere from 23 days to 35 days.
The parts of the body involved in the menstrual cycle include the brain,
pituitary gland, uterus and cervix, ovaries, fallopian, tubes,
and vagina. Body chemicals called hormones rise and
fall during the month and make the menstrual cycle happen. The ovaries make two
important female hormones, estrogen
and progesterone.
Other hormones involved in the menstrual cycle include follicle-stimulating
hormone (FSH) and luteinizing hormone (LH), made by the pituitary
gland.
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In the first half of the menstrual cycle, levels of estrogen rise and make
the lining of the uterus grow and thicken. In response to follicle-stimulating
hormone, an egg (ovum) in one of the ovaries starts to mature. At about day
14
of a typical 28-day cycle, in response to a surge of luteinizing hormone, the
egg leaves the ovary. This is called ovulation.
In the second half of the menstrual cycle, the egg begins to travel through
the fallopian tube to the uterus. Progesterone levels rise and help prepare the
uterine lining for pregnancy. If the egg becomes fertilized by a sperm cell and
attaches itself to the uterine wall, the woman becomes pregnant. If the egg is
not fertilized, it either dissolves or is absorbed into the body. If pregnancy
does not occur, estrogen and progesterone levels drop, and the thickened lining
of the uterus is shed during the menstrual period.
In the illustration below, an egg has left an ovary after ovulation and is
on
its way through a fallopian tube to the uterus.
Image Source: U.S. Food and Drug Administration
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During the menstrual period, the thickened uterine lining and extra blood
are shed through the vaginal canal. A woman's period may not be the same every
month, and it may not be the same as other women's periods. Periods can be
light, moderate, or heavy, and the length of the period also varies. While most
menstrual periods last from three to five days, anywhere from two to seven
days
is considered normal. For the first few years after menstruation begins, periods
may be very irregular. They may also become irregular in women approaching
menopause.
Sometimes birth control pills are prescribed to help with irregular periods or
other problems with the menstrual cycle.
Sanitary pads or tampons, which are made of cotton or another absorbent
material, are worn to absorb the blood flow. Sanitary pads are placed inside the
panties; tampons are inserted into the vagina.
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Women can have various kinds of problems with their periods, including pain,
heavy bleeding, and skipped periods.
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Amenorrhea - the lack of a menstrual period. This term
is used to describe the absence of a period in young women who haven't started
menstruating by age 16, or the absence of a period in women who used to have a
regular period. Causes of amenorrhea include pregnancy, breastfeeding, and
extreme weight loss caused by serious illness, eating disorders, excessive
exercising, or stress. Hormonal problems (involving the pituitary, thyroid,
ovary, or adrenal glands) or problems with the reproductive organs may be
involved.
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Dysmenorrhea - painful periods, including severe
menstrual cramps. In younger women, there is often no known disease or
condition associated with the pain. A hormone called prostaglandin is
responsible for the symptoms. Some pain medicines available over the counter,
such as ibuprofen, can help with these symptoms. Sometimes a disease or
condition, such as uterine
fibroids or endometriosis,
causes the pain. Treatment depends on what is causing the problem and how
severe it is.
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Abnormal uterine bleeding-vaginal bleeding that is different
from normal menstrual periods. It includes very heavy bleeding or unusually
long periods (also called menorrhagia), periods too close together,
and bleeding between periods. In adolescents and women approaching menopause,
hormone imbalance problems often cause menorrhagia along with irregular
cycles. Sometimes this is called dysfunctional uterine bleeding (DUB). Other
causes of abnormal bleeding include uterine fibroids and polyps. Treatment for
abnormal bleeding depends on the cause.
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Menarche is another name for the beginning of menstruation. In the
United States, the average age a girl starts menstruating is 12. However, this
does not mean that all girls start at the same age. A girl can begin
menstruating anytime between the ages of 8 and 16. Menstruation will not occur
until all parts of a girl's reproductive system have matured and are working
together.
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Women usually continue having periods until menopause. Menopause occurs
around the age of 51, on average. Menopause means that a woman is no longer
ovulating (producing eggs) and therefore can no longer become pregnant. Like
menstruation, menopause can vary from woman to woman and may take several years
to occur. Some women have early menopause because of surgery or other treatment,
illness, or other reasons.
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You should consult your health care provider for the following:
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If you have not started menstruating by the age of 16.
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If your period has suddenly stopped.
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If you are bleeding for more days than usual.
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If you are bleeding excessively.
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If you suddenly feel sick after using tampons.
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If you bleed between periods (more than just a few drops).
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If you have severe pain during your period.
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Sanitary napkins (pads) should be changed as often as necessary, before the
pad is soaked with menstrual flow. Each woman decides for herself what is
comfortable. Tampons should be changed often (at least every 4-8 hours). Make
sure that you use the lowest absorbency of tampon needed for your flow. For
example, do not use super absorbency on the lightest day of your period. This
can put you at risk for toxic shock syndrome (TSS). TSS is a rare but
potentially deadly disease. Women under 30, especially teenagers, are at a
higher risk for TSS. Using any kind of tampon - cotton or rayon of any
absorbency - puts a woman at greater risk for TSS than using menstrual pads. The
risk of TSS can be lessened or avoided by not using tampons, or by alternating
between tampons and pads during your period.
The Food and Drug Administration (FDA) recommends the following tips to help
avoid tampon problems:
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Follow package directions for insertion.
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Choose the lowest absorbency for your flow.
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Change your tampon at least every 4 to 8 hours.
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Consider alternating pads with tampons.
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Know the warning signs of toxic shock syndrome (see below).
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Don't use tampons between periods.
If you experience any of the following symptoms while you are menstruating
and using tampons, you should contact your health care provider immediately:
National Women's Health Information Center
(NWHIC)
Food and Drug
Administration
American College
of Obstetricians and Gynecologists (ACOG) Resource Center
Nemours Foundation
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Abnormal Vaginal Bleeding
