Luke, and Jenna are rushing to math class when Tori ducks into the
restroom. Jenna knows Tori has her period and she's a little envious,
wondering when hers is going to start - even her 10-year-old little
sister has hers. What she doesn't know is that Tori has cramps and
is wishing she'd never gotten her period in the first place. Meanwhile
Luke, who's Tori's twin, is wondering if she's OK. He knows his
sister has her period but can't imagine what it feels like. Does
she know it's coming? Can she bleed too much?
Menstruation (a period) represents a major stage of puberty in
girls; it's one of the many physical signs that a girl is turning
into a woman. And like a lot of the other changes associated with
puberty, menstruation can be confusing for girls (and guys). Some
girls can't wait to start their periods, whereas others may feel
afraid or anxious. Many girls and guys don't have a complete
understanding of a woman's reproductive system or what actually
happens during the menstrual cycle, making the process seem even
Puberty and Period
When girls begin to go through puberty (usually starting between
the ages of 8 and 13), their bodies and minds change in many ways.
The hormones in their bodies stimulate new physical development,
such as growth and breast development. About 2 to 2 1/2 years after
a girl's breasts begin to develop, she usually gets her first menstrual
About 6 months or so before getting her first period, a girl might
notice an increased amount of clear vaginal discharge. This discharge
is common. There's no need for a girl to worry about discharge unless
it has a strong odor or causes itchiness.
The start of periods is known as menarche (pronounced:
meh-nar-kee). Menarche doesn't happen until all
the parts of a girl's reproductive system have matured and are working
girls are born with ovaries, fallopian tubes, and a uterus. The
two ovaries are oval-shaped and sit on either side of the uterus
(womb) in the lowest part of the abdomen called the pelvis. They
contain thousands of eggs, or ova. The two fallopian tubes are long
and thin - like hollow strands of spaghetti (only a little bit thicker).
Each fallopian tube stretches from an ovary to the uterus, a pear-shaped
organ that sits in the middle of the pelvis. The muscles in a female's
uterus are powerful and are able to expand to allow the uterus to
accommodate a growing fetus and then help push the baby out during
As a girl matures and enters puberty, the pituitary gland releases
hormones that stimulate the ovaries to produce other hormones called
estrogen and progesterone. These hormones have many effects on a
girl's body, including physical maturation, growth, and emotions.
About once a month, a tiny egg leaves one of the ovaries - a process
called ovulation - and travels down one of the fallopian tubes toward
the uterus. In the days before ovulation, the hormone estrogen stimulates
the uterus to build up its lining with extra blood and tissue, making
the walls of the uterus thick and cushioned. This happens to prepare
the uterus for pregnancy: If the egg reaches the uterus and is fertilized
by a sperm cell, it attaches to the cushiony wall of the uterus,
where it slowly develops into a baby.
If the egg isn't fertilized, though - which is the case during
most of a girl's monthly cycles - it doesn't attach to the wall
of the uterus. When this happens, the uterus sheds the extra tissue
lining. The blood, tissue, and unfertilized egg leave the uterus,
going through the vagina on the way out of the body. This is a menstrual
period. This cycle happens almost every month for several more decades
(except, of course, when a female is pregnant) until a woman reaches
menopause and no longer releases eggs from her
How Often Does a Girl Get Her Period?
Just as some girls begin puberty earlier or later than others, the
same applies to periods. Some girls may start menstruating as early
as age 9 or 10, but others may not get their first period until
later in their teens. The amount of time between a girl's periods
is called her menstrual cycle
(the cycle is counted from the start of one period to the start
of the next). Some girls will find that their menstrual cycle lasts
28 days, whereas others might have a 24-day cycle, a 30-day cycle,
or even a 35-day cycle.
Irregular periods are common in girls who are just beginning to
menstruate. It may take the body a while to sort out all the changes
going on, so a girl may have a 28-day cycle for 2 months, then miss
a month or have two periods with hardly any time in between them,
for example. Usually, after a number of months, the menstrual cycle
will become more regular. Many women continue to have irregular
periods into adulthood, though.
As a girl gets older and her periods settle down - or she gets
more used to her own unique cycle - she will probably find that
she can predict when her period will come.
How Long and How Much?
The amount of time that a girl has her period also can vary. Some
girls have periods that last just 2 or 3 days; other girls may have
periods that last 7 days or longer. The menstrual flow - meaning
how much blood comes out of the vagina - can vary widely from person
to person, too. Some girls have such light blood flow that they
wonder if they even have their period at all.
Other girls may be concerned that they're losing too much blood.
It can be a shock to see all that blood, but it's highly unlikely
that a girl will lose too much: For most girls an entire period
consists of anywhere from a few spoonfuls to less than 1/2 cup (118
milliliters) of blood - it just looks like a lot! (It is possible
for a girl to lose an excessive amount of blood during her period,
but it's not at all common. In some cases, a female will bleed too
much because she has a medical condition - such as von Willebrand disease.)
The amount of blood a girl loses and how long her period lasts can
differ from month to month.
If you're worried about your blood flow or whether your period
is normal in other ways, talk to a doctor or nurse. Some changes
in menstrual periods can be normal - but only a doctor can help
determine the cause of irregular, heavy, or painful periods - or
no periods at all.
Cramps, PMS, and Pimples
Some girls may notice physical or emotional changes around the time
of their periods. Menstrual cramps are pretty common - in fact,
more than half of all women who menstruate say they have cramps
during the first few days of their periods. Doctors think that cramps
are caused by prostaglandins, a chemical that causes the muscles
of the uterus to contract.
Depending on the person, menstrual cramps can be dull and achy
or sharp and intense, and they can sometimes be felt in the back
or the thighs as well as the abdomen. These cramps often become
less uncomfortable and sometimes even disappear completely as a
girl gets older. In the meantime, many girls and women find that
taking an over-the-counter pain medication like acetaminophen or
ibuprofen can provide relief from menstrual cramps. Taking
a warm bath or applying a warm heating pad to your lower abdomen
can sometimes help, too. Exercising regularly throughout the monthly
cycle may also help lessen cramps in some people. If these things
don't help, ask your doctor for advice.
Some girls and women find that they feel depressed or easily irritated
during the few days or week before their periods. Others may get
angry more quickly than normal or cry more than usual. Some girls
crave certain foods. These types of emotional changes may be the
result of premenstrual syndrome, or PMS.
PMS is related to changes in the body's hormones. As hormone levels
rise and fall during a woman's menstrual cycle, they can affect
the way she feels, both emotionally and physically. Some girls,
in addition to feeling more intense emotions than they usually do,
notice physical changes along with their periods - some feel bloated
or puffy because of water retention, others notice swollen and sore
breasts, and some get headaches. PMS usually goes away soon after
a period begins, but it can come back month after month. Doctors
recommend that girls with PMS try to exercise to help feel better.
And some girls notice that restricting caffeine intake may help
It's not uncommon for girls to have an acne flare-up during certain
times of their cycle; again, this is due to hormones. Fortunately,
the pimples associated with periods tend to become less of a problem
as girls get older.
Pads, Tampons, and Liners
Once you begin menstruating, you'll need to use something to soak
up the blood - either a pad or a tampon. There are so many products
out there that it may take some experimenting before you find the
one that works best for you. Some girls use only pads (particularly
when they first start menstruating), some use only tampons, and
some girls switch around - tampons during the day and pads at night,
for example. Girls who are very active, particularly girls who enjoy
swimming, often find that tampons are the best option during sports.
Periods shouldn't get in the way of exercising, having fun, and
enjoying life. If you have questions about pads, tampons, or coping
with periods, ask a parent, health teacher, school nurse, or older