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.
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
, 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
. 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.
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.
In this illustration, the menstrual cycle is divided into four
stages. First, an egg matures inside the ovary (1), which then
releases the egg (2), allowing it to travel through the fallopian
tube, where it rests awaiting fertilization (3). If the egg is not
fertilized, it is flushed out with the menstrual flow (4).
(Illustration by GGS Information Services.)
is the medical term for menstrual cramps, the dull or throbbing
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:
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
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.
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
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:
These symptoms usually stop or lessen a day or two after the period
There are several reasons why a girl should see her healthcare provider
regarding her menstrual cycle. These include:
No specific medical treatment is necessary for an uncomplicated menstrual
cycle, as it is a normal, healthy process in girls and women.
Some girls may find relief from menstrual discomfort through meditation,
, or massage. These stress-relieving activities are unlikely to cause any
—The first menstrual cycle in a girl's life.
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Period: A Girl's Guide to Menstruation.
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Chumlea, William Cameron, et al. "Age at Menarche and Racial
Comparisons in U.S. Girls."
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American College of Obstetricians and Gynecologists.
409 12th Street, SW, PO Box 96920, Washington, DC 20090–6290. Web
The Center for Young Women's Health.
300 Longwood Avenue, Box 310, Boston, MA 02115. Web site:
"Frequently Asked Questions about Menstruation and the Menstrual
4woman.gov-The National Women's Health Information Center
, November 2002. Available online at
http://www.4woman.gov/faq/menstru.htm (accessed October 25,
"Period Talk: Preparing Your Preteen for Menstruation."
Available online at
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