PMS Resource
Center
Menstruation
and the Menstrual Cycle
article syndicated from NWHIC
November 2002
What is menstruation?
What is the menstrual cycle?
What happens during the menstrual cycle?
What is a typical menstrual period like?
What kinds of problems do women have
with their periods?
At what age does a girl get her first
period?
How long does a woman have periods?
When should I see a health care provider
about my period?
How often should I change my pad/tampon?
What is menstruation?
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.
What is the menstrual cycle?
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.
What happens during the menstrual cycle?
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
What is a typical menstrual period like?
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.
What kinds of problems do women have
with their periods?
Women
can have various kinds of problems with their periods,
including pain, heavy bleeding, and skipped
periods.
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.
-
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.
-
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.
At what age does a girl get her first
period?
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.
How long does a woman have periods?
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.
When should I see a health care provider
about my period?
You
should consult your health care provider for the following:
If you have not started menstruating
by the age of 16.
-
If your period has suddenly stopped.
-
If you are bleeding for more days
than usual.
-
If you are bleeding excessively.
-
If you suddenly feel sick after using
tampons.
-
If you bleed between periods (more
than just a few drops).
-
If you have severe pain during your
period.
How often should I change my pad/tampon?
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:
Follow package directions for insertion.
-
Choose the lowest absorbency for
your flow.
-
Change your tampon at least every
4 to 8 hours.
-
Consider alternating pads with tampons.
-
Know the warning signs of toxic shock
syndrome (see below).
-
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:
article
syndicated from National
Women's Health Information Center (NWHIC):
http://www.4woman.gov/faq/menstru.htm
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