PMS Resource
Center
On
the Teen Scene: A Balanced Look at the Menstrual
Cycle
by Marian Segal
This article is part of a series with important health
information for teenagers.
Some young women feel it coming days before they
get it. Others are hardly aware they have it. Friends
who compare notes about their periods will probably
find that menstruation--the monthly shedding of the
lining of the uterus, or womb-affects each of them
a little differently, both physically and emotionally.
"The menstrual cycle has its ups and downs of
hormones, and different people react differently to
hormonal swings," says Lisa Rarick, M.D., a gynecologist
in FDA's Center for Drug Evaluation and Research. She
explains that just before and during menstruation,
levels of the female hormones estrogen and progesterone
are low. That's when some women feel bloated, irritable
or blue, or "just crummy," she says.
"Just crummy" might
mean cramps, sore breasts, backache, headache, nausea,
and feeling tired.
"A
day or two after your period starts you begin to
feel better. Hormone levels go back on the upswing
and you get back to what you're accustomed to during
the rest of your cycle," Rarick explains. (See "Monthly
Changes.")
Cramps--A Common Complaint
More than half of menstruating women have cramp-like
pain during their periods. The medical term for menstrual
pain is dysmenorrhea. Cramps are usually felt in the
pelvic area and lower abdomen, but can radiate to the
lower back or down the legs.
"Many girls have cramps severe enough to keep
them home from school," Rarick says. In fact,
according to Danforth's Obstetrics and Gynecology,
dysmenorrhea is the most frequent cause of absenteeism
from school among younger women. Rarick says women
seem to go through phases when cramps are severe, then
get better for several years, and then maybe worsen
again. She adds that most women find they have less
menstrual pain after having children.
Mechanically, cramps are like labor pains. Just as
the uterus contracts to open up the cervix (neck of
the uterus) and push out a baby, it contracts to expel
menstrual blood. Often, after several years of menstruating
or after childbirth, the cervical opening enlarges.
The uterus doesn't have to contract as much to discharge
the menstrual flow, so there is less cramping.
Menstrual pain may also come from the bleeding process
itself. When the uterine lining separates from the
wall, it releases chemicals called prostaglandins.
Prostaglandins cause blood vessels to narrow, impeding
the supply of oxygen to the uterus. Just as the pain
of a heart attack comes from insufficient blood to
the muscles of the heart, too little blood to the uterine
muscle might cause the pain of menstrual cramps.
Menstrual pain can have other causes, although these
are rare among teenagers. They include tumors, fallopian
tube infection, and endometriosis, a condition in which
fragments of the lining of the uterus become embedded
elsewhere in the body (see "On
the Teen Scene: Endometriosis--Painful but Treatable" in
the January-February 1993 FDA Consumer).
Pain, Pain Go Away
Sometimes, simple measures are all that's needed
to feel better. Cutting down on salt might help reduce
fluid buildup, and support hose may alleviate swelling
in the legs or ankles. Crawling into bed for some extra
rest or sleep is one way to deal with fatigue, and
taking along a heating pad or hot water bottle eases
cramps for some. Exercising also helps reduce pain
in many young women, and may lift a blue mood as well.
Charles Debrovner, M.D., associate clinical professor
of obstetrics and gynecology at New York University
School of Medicine, explains that exercising during
menstruation lessens pain because it causes release
of brain chemicals called endorphins, which are natural
painkillers. He says exercise may also decrease pain
by affecting prostaglandin metabolism.
Rarick
adds that exercise may also help because it increases
blood flow, and
because it "just makes a lot of people feel
better in general."
If symptoms interfere with work, school or sleep,
the American College of Obstetricians and Gynecologists
recommends seeing a doctor, who may suggest taking
one or more medicines. Certain anti-inflammatory drugs
called NSAIDs (an abbreviation for nonsteroidal anti-inflammatory
drugs) inhibit prostaglandin production, thus easing
cramps. Prescription NSAIDs include naproxen (Naprosyn,
Anaprox), ibuprofen (Motrin, IBU), indomethacin (Indocin),
and mefenamic acid (Ponstel).
If needed, your doctor may prescribe stronger painkillers
or diuretics, or even oral contraceptives. One side
effect of birth control pills is relief of menstrual
cramps.
"Birth control pills work two ways to lessen
cramps," says Rarick. "They prevent the lining
of the uterus from building up so much, so there's
less bleeding. This means less prostaglandin production
and blood vessel narrowing because there's less lining
to separate, and fewer contractions because there's
less tissue to push out."
Over-the-Counter Relief
In
1984, FDA approved ibuprofen in over-the-counter (OTC)
strengths to be sold without a prescription.
It's the active ingredient in medicines such as Advil,
Nuprin and Motrin IB. In 1994, the agency approved
naproxen for OTC marketing in lower doses than the
prescription strength. OTC naproxen is sold under the
brand name Aleve.
Like NSAIDs, aspirin also suppresses prostaglandins,
but it's often not as effective as other NSAIDs for
menstrual pain. Aspirin should never be used by children
or teenagers who have chickenpox or flu symptoms before
checking with a doctor. This is because Reye syndrome,
a rare but sometimes deadly illness, may develop in
children and teenagers who have taken aspirin or products
that contain it while they were sick with chickenpox
or flu.
Several OTC products, such as Midol and Pamprin,
are specifically formulated for menstrual symptoms.
Read the labels of these medicines before you buy them,
because different formulations often contain different
ingredients or strengths of ingredients. For example,
Teen Formula Midol contains acetaminophen for pain
and pamabrom (a mild diuretic) for fluid retention.
Pamprin contains acetaminophen, pamabrom and pyrilamine
maleate (an antihistamine) for tension and irritability.
Cramp Relief Formula Midol IB contains as its sole
ingredient ibuprofen. Manufacturers may change their
products' ingredients from time to time, so it's a
good idea to check the label each time you buy the
product.
Plain acetaminophen products like Tylenol, Datril,
and Aspirin-Free Anacin also may help menstrual pain.
It takes time for pain relievers to work, so it's best
to take them before the pain gets bad and continue
for one or two days, as needed.
Some 20 to 40 percent of menstruating women have
PMS, or premenstrual syndrome. Starting anywhere from
mid-cycle to a few days before menstruation begins,
women with PMS may have one or all of a virtual laundry
list of physical and emotional symptoms. They include
breast swelling and tenderness, fluid retention, increased
thirst or appetite, craving for sweets and salty foods,
headaches, anxiety, restlessness, irritability, depression,
hostility, and loss of self confidence. Experts say
PMS doesn't usually affect teenagers, though. It increases
with age and is more prevalent in the 30s and 40s.
From Menarche to Menopause
In the United States, the average age of menarche--a
girl's first period-is 12 years, although it's normal
to start as early as 10 or as late as 16. Menopause--when
periods stop-usually occurs around age 50, although
that, too, can vary by several years. Except perhaps
for the first two years of menstruation-and barring
pregnancy, nursing, and certain illnesses or other
problems-the reproductive cycle repeats with predictable
regularity every month.
Exercise, diet and stress can delay the onset of
menstruation, Rarick says, or alter cycles once they've
been established.
"Gymnasts, ballerinas and others who exercise
strenuously can sometimes delay the onset of their
periods, so you might not be surprised to find a 16-
or 17-year-old in that group who hasn't started menstruating," she
says. "Some experts believe the connection between
exercise and amenorrhea [the absence of menstrual periods]
is related to body fat content, because fat affects
estrogen. Young women who are very thin from malnourishment
may not start menstruating until they gain weight,
with a certain portion of that weight being fat. So,
girls who exercise a lot-who are all bone and muscle
with no fat-may delay their periods."
Similarly, young women with severe eating disorders
such as anorexia or bulimia often do not menstruate.
(See "On the Teen Scene:
Eating Disorders Require Medical Attention" in
the March 1992 FDA Consumer).
The American College of Obstetricians and Gynecologists
recommends that a girl see her doctor if she hasn't
started menstruating by age 16, or if by age 13 or
14 she hasn't begun to develop breasts or pubic and
underarm hair.
Just Like Clockwork?
Many
young women have very irregular periods the first couple
years of
menstruating--even skipping some
months, until, as Rarick says, "the system is
well-tuned."
In addition, she says, young women don't always ovulate
every month when they first get their periods. She
adds that there's no sure way for a young woman to
know which month she is ovulating and which she is
not. So, from the time her periods begin, a young woman
should assume she can get pregnant each and every month,
even if her periods are irregular.
Eventually, periods become regular, but even when
they do, a missed or late period once a year--especially
at a stressful time--is considered normal, according
to Rarick.
Also, just as strenuous exercise and eating disorders
can delay the onset of menstruation, they can also
cause previously regular menstrual cycles to become
irregular or stop completely.
Marian Segal is a member of FDA's public
affairs staff.
Technical Talk
amenorrhea: the
absence of menstrual periods
dysmenorrhea: pain
or discomfort during menstruation
fallopian
tubes: two slender tubes-one
on either side of the uterus--that carry the egg (ovum)
from the ovary to the uterus
menarche: a
young woman's first period
mittelschmerz: pain
or discomfort during ovulation
ovaries: two
female reproductive organs--one on either side of
the uterus--that contain
the eggs, or ova, and make hormones
ovulation: release
of an egg from the ovary
prostaglandin: a
chemical made by the body that causes the muscle
of the uterus to contract,
often causing cramps
uterus
(womb): the female organ
in which a fertilized egg grows and develops into a
baby
Monthly Changes
Menstruation
is just one part of the menstrual cycle, in which
a woman's body prepares for pregnancy each month.
A cycle is counted from the first day of one period
to
the first day of the next. An average cycle is 28
days, but anywhere from 23 to 35 days is normal.
Estrogen and progesterone levels are very low at
the beginning of the cycle. During menstruation, levels
of estrogen, made by the ovaries, start to rise and
make the lining of the uterus grow and thicken. In
the meantime, an egg (ovum) in one of the ovaries starts
to mature. It is encased in a sac called the Graafian
follicle, which continues to produce estrogen as the
egg grows.
At about day 14 of a typical 28-day cycle, the sac
bursts and the egg leaves the ovary, traveling through
one of the fallopian tubes to the uterus. The release
of the egg from the ovary is called ovulation. Some
women know when they're ovulating, because at mid-cycle
they have some pain--typically a dull ache on either
side of the lower abdomen lasting a few hours. The
medical word for this is mittelschmerz, from the German,
meaning middle pain. Some women also have very light
bleeding, or spotting, during ovulation.
After the egg is expelled, the sac--now called a
corpus luteum--remains in the ovary, where it starts
producing mainly progesterone. The rising levels of
both estrogen and progesterone help build up the uterine
lining to prepare for pregnancy.
The
few days before, during and after ovulation are a
woman's "fertile period"-the
time when she can become pregnant. Because the length
of menstrual
cycles vary, many woman ovulate earlier or later than
day 14. It's even possible for a woman to ovulate while
she still has her period if that month's cycle is very
short. (Stress and other things can sometimes cause
a cycle to be shorter or longer.) If a woman has sex
with a man during this time and conception occurs (his
sperm fertilizes the egg), she becomes pregnant.
The fertilized egg attaches to the uterus, and the
corpus luteum makes all the progesterone needed to
keep it implanted and growing until a placenta (an
organ connecting the fetus to the mother) develops.
The placenta then makes hormones and provides nourishment
from the mother to the baby.
If an egg is not fertilized that month and the woman
doesn't get pregnant, the corpus luteum stops making
hormones and gets reabsorbed in the ovary. Hormone
levels drop again, the lining of the uterus breaks
down, menstruation begins, and the cycle repeats.
In
the illustration below, an egg has left an ovary
after ovulation and is on its way through a fallopian
tube to the uterus.
Menstrual Bleeding:
What's Normal, What's Not
Most menstrual periods last from three to five days,
but anywhere from two to seven days is normal. The amount
of blood flow varies, too, but for most women, bleeding
starts out light at first, followed by heavier flow for
a day or two and then another light day or two. 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.
"The amount of bleeding varies from woman to
woman because everybody's body has a different way
of building up the lining of the uterus," says
Lisa Rarick, M.D. "A lighter flow or heavier flow
doesn't mean you can't get pregnant as easily or you're
never going to get pregnant, or that your periods will
always stay the same way. But if you're bleeding excessively-soaking
one or more tampons or pads an hour-you should see
a doctor to see if there's a problem."
Rarick, a gynecologist with FDA's Center for Drug
Evaluation and Research, says teenagers often are concerned
if they expel blood clots during their periods. She
says this is not dangerous; they are clumps of pooled
blood in the vagina. Sometimes, instead of flowing
freely, blood drains from the uterus and stays in the
vagina until there's a change in position--say, from
sitting to standing.
Women
who use tampons should be aware of toxic shock syndrome,
or TSS, a rare but serious-and sometimes
fatal-disease that's been associated with tampon use.
Tampon packages carry information about TSS on the
box or inside. Because TSS mostly affects 15- to 19-year-olds,
it's especially important for teenagers to know what
signs to look for. If you develop the following symptoms
while menstruating, remove the tampon and get medical
help right away:
-
-
dizziness,
fainting,
or
near
fainting
when
standing
up
a
rash that
looks like
a sunburn.
For
more on toxic shock syndrome, see "On the
Teen Scene: TSS-Reducing the Risk" in the
October 1991 FDA Consumer.
article
syndicated from U.S.
Food and Drug Administration:
http://www.fda.gov/fdac/reprints/ots_mens.html
FDA Consumer Magazine - December 1993
Publication No. (FDA) 94-1215
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