Dysmenorrhea (menstrual cramps) is one of the most common
problems suffered by women of childbearing age. It's estimated
that between 30 and 50 percent of women suffer from pain during
their menstrual period, and of these, 15 percent would describe
their menstrual cramps as severe. Some women's menstrual cramps
are so severe, they must curtail their normal activities—any
movement or activity is too painful.
Menstrual cramps should not be confused with the discomfort experienced
during premenstrual syndrome (PMS),
although the symptoms of both disorders can sometimes be experienced
as a continual process. PMS, characterized by a combination of
emotional, physical, psychological, and mood disturbances, occurs
after a woman's ovulation and normally ends with the onset of
her menstrual flow. Menstrual cramps usually occur shortly before
or during the first few days of a woman's menstrual period, peaking
within 24 hours after onset, and subsiding again after about a
day or two. Cramps may be barely noticeable, feeling like a light
heaviness in the belly, or they may be so painful, they may interfere
with a woman's normal activities for several days. In addition
to abdominal pain, cramp sufferers also experience backache, pinching
and pain sensations in the inner thighs, bloating, nausea, vomiting,
diarrhea, constipation, faintness, dizziness, fatigue, and headaches.1
The normal menstrual cycle
To better understand why painful menstruation occurs, it's important
to look at the normal menstrual cycle and see how it functions.
Menstruation refers to the shedding of the endometrium,
or uterine lining. Every month, in anticipation of housing and nourishing
a fertilized egg, the uterus prepares a thick, blood-rich cushion. If
fertilization doesn't occur and a fertilized egg doesn't implant in the
uterus, this extra blood and tissue are not needed by the body; the uterus
then cleanses itself by shedding this lining so that a fresh buildup can
occur the following month, in anticipation of a possible pregnancy.
The buildup and shedding of the uterine lining is a complex mechanism
controlled by the fluctuations in a woman's hormone levels. Each month,
the pituitary gland releases follicle stimulating hormones (FSH)
and luteinizing hormones (LH) into the bloodstream where they can
be carried to the ovaries, the tiny sacs that contain all the eggs a woman
will ever have. Eggs in the ovaries exist in an inactive form called
follicles. During each menstrual cycle, the FSH and LH from the
pituitary gland cause one follicle to ripen, and a normal ovum (egg)
is released for fertilization. As a normal part of this process, the
follicle begins to produce the hormones estrogen and
In addition to preparing the egg for fertilization, estrogen and
progesterone stimulate the lining of the uterus. During the first two weeks
following a woman's menstrual cycle, estrogen stimulates the rebuilding of
the uterine lining. The inner mucus layer of endometrial glands start to
grow long and through an increase in the number of blood vessels as well as
the production of a mesh of fibers that interconnect throughout the lining,
the endometrium thickens.
By mid-cycle (day 14), the lining of the uterus has increased three
times in thickness and has a greatly increased blood supply. After day 14,
ovulation occurs: the egg travels through the fallopian tube to the uterus.
After mid-cycle, the graafian follicle that produced the egg for that
month is further stimulated by LH and changes into a corpus luteum, a
yellow body that secretes progesterone. Progesterone affects the uterine
lining by causing a coiling of the blood vessels of the lining, which itself
becomes swollen and secretes a thick mucus.
If fertilization occurs, the egg will implant itself in the uterine
wall and the corpus luteum will continue to secrete progesterone. However,
if fertilization does not occur, the corpus luteum begins to deteriorate
and progesterone levels decrease. The lining of the uterus breaks down
and menstruation begins.
During the breakdown of the uterine lining, molecular compounds called
prostaglandins are released. Prostaglandins and in particular,
prostaglandin F2alpha (PGF2alpha), cause the muscles of the uterus
to contract, thereby constricting the blood supply to the endometrium. This
contraction interferes with the oxygenation of endometrial tissue which, in
turn, breaks down and dies. After the death of this tissue, uterine
contractions literally squeeze the old endometrial tissue through the cervix
and out of the body by way of the vagina. The pain of cramps is intensified
when clots or pieces of bloody tissue from the lining of the uterus pass
through the cervix, especially if a woman's cervical canal is narrow.
The intensity of menstrual pain is related to a woman's prostaglandin
levels. Prostaglandin levels are 5 to 13 times higher in women who
experience menstrual cramps than in women who do not experience menstrual
cramps. The pain of menstrual cramps is similar to the pain experienced by
a pregnant woman when she is given prostaglandin as a medication to induce
Types of menstrual cramps/dysmenorrhea
Menstrual cramps or dysmenorrhea may be of two types, primary
Most women, by far, suffer from the primary type of dysmenorrhea.
Typically beginning at the start of menstruation (menarche), that
time when a young girl begins having menstrual periods, the painful cramps
of primary dysmenorrhea cannot be attributed to any gynecologic problem.
The pain itself is the main problem.
Primary dysmenorrhea can be further classified into two sub-types:
primary spasmodic dysmenorrhea or congestive dysmenorrhea.
Primary spasmodic dysmenorrhea most commonly affects young women in their
teens to late twenties and is more common in women who have never borne
children. Childbearing, in fact, seems to mark the end of primary
spasmodic dysmenorrhea in many women.
Primary spasmodic dysmenorrhea
Primary spasmodic dysmenorrhea is characterized by sharp, vise-like pains
caused by the constriction and tightening of the uterine muscle. This
pain is occasionally accompanied by sharp pains in the inner thighs and
low abdominal muscles, of hot and cold, faintness to the point of passing
out; nausea, vomiting, and bowel changes varying from constipation to
What causes this pain and cramping? The uterine muscle and
the blood vessels that supply the uterus are tight and contracted.
The metabolism of the uterus and pelvic muscles is decreased
as a result of reduced blood circulation and oxygenation. The
increase in carbon dioxide and lactic acid—waste products
of metabolism Ὰ intensifies pain and discomfort.
Primary congestive dysmenorrhea
Different from the pain of spasmodic cramping, the pain that
characterizes primary congestive dysmenorrhea produces a dull
aching in the lower back and pelvic region—a pain often
accompanied by bloating, weight gain, breast tenderness (mastalgia),
headaches, and irritability. Unlike spasmodic cramping, symptoms
don't improve with age and in some cases, may actually worsen.
Some of the most severe symptoms are seen in women in their
thirties and forties.
Are there any risk factors that contribute the pain and discomfort
of primary dysmenorrhea? Yes, there are a number of risk factors
that can contribute to both spasmodic and congestive menstrual
- Use of tampons
- Women who find that the use of tampons exacerbates
their cramps should switch to sanitary napkins.
- Use of an IUD
- Use of an intrauterine device
(IUD) can significantly worsen the
spasmodic type of cramping; the IUD may need to be removed if symptoms
- Bladder infections
- Frequent bladder infections near or during menstrual periods can
cause a dull, aching pain in the lower abdomen.
- Yeast vaginitis/yeast infections
- Changes in vaginal pH during menstruation can cause vaginal yeast
infections during menstrual periods.
- Spasmodic cramping is typically worse in women who have not borne
children; congestive symptoms are typically worse in women who have had
- Lack of exercise/poor posture
- Lack of exercise and poor posture interfere with blood circulation
and oxygenation and increase the tendencies toward both types of cramps.
- By causing women to tense back and pelvic muscles unconsciously,
stress can worsen cramps.
Although sometimes evident at menarche, secondary dysmenorrhea
usually develops later. Some underlying abnormal condition involving a
woman's reproductive system contributes to menstrual pain.
Far less common than primary dysmenorrhea, secondary dysmenorrhea
is most commonly seen among women in their forties and fifties.
After years of pain-free menstruation, periods may suddenly become
painful. Secondary dysmenorrhea is the result of underlying health
problems such as fibroid tumors of the uterus, fibroid tumors
stimulated by estrogen, pelvic inflammatory
disease (PID), and endometriosis—conditions that can
cause uterine and low back pain.
How are menstrual cramps diagnosed?
Diagnosis of menstrual cramps is usually made by the woman herself
and is a reflection of her perception of pain. Once a woman has experienced
menstrual cramps, she usually becomes familiar with their symptoms. For
most women, body awareness and knowing how to maintaining optimal health
allows them to manage the pain of menstrual cramps.
How are menstrual cramps treated?
Treatment of menstrual cramps should be tailored to each woman's individual
needs. The most common treatment is to lie down at the first sign of pain.
Although adequate rest and sleep are strongly advised, current
recommendations also include regular exercise, particularly walking. Some
women report a decrease in pain as a result of abdominal massage, yoga, or orgasmic
sexual activity. A heating pad applied to the abdominal area can also help
relieve pain and congestion.
A number of non-prescription (over-the-counter) medications can not
only help control pain, but they can also help prevent cramps themselves.
Medications such as Aspirin or acetaminophen (Tylenol) or acetaminophen
plus a diuretic (e.g. Diurex MPR, FEM-1, Midol, Pamprin, Premsyn, and others)
may be enough to alleviate mild cramps.
In the case of moderate cramps, non-steroidal anti-inflammatory drugs
(NSAIDs) lower the production of prostaglandin and lessen its effect.
Table 1. NSAIDs used to treat dysmenorrhea
Ibuprofen (e.g. Advil, Anaprox, Midol IB, Motrin, Nuprin,
Naproxen (e.g. Aleve)
Ketoprofen (e.g. Actron, Orudis KT)
mefenamic acid (Ponstel)
Such medications should be taken before pain becomes difficult to
manage; this may mean starting medications 1 to 2 days before a menstrual
period is due to start and continuing taking medication 1 to 2 days into
a period. Routinely taking NSAIDs is more effective than waiting for the
onset of pain to take them.
In the case of severe cramps, a woman may be prescribed low-dose
oral contraceptives containing
estrogen and progestin or long-acting
edroxyprogesterone. By preventing ovulation and reducing the production
of prostaglandins, these medications can reduce the severity of cramping
and cause a light menstrual flow.
In the past, women who suffered severe menstrual cramps underwent a surgical
procedure known as dilation and curettage (D&C) to remove some
of the lining of the uterus. Other women resorted to hysterectomy,
a surgery that removes the entire uterus. Today, modern techniques such
as endometrial ablation allow women to retain their uterus while providing
pain relief. During endometrial ablation, the lining of the uterus is
burned away using a heat-generating device.
In the case of secondary dysmenorrhea,
treatment depends on the cause. As we've seen, pain may be attributed
to any number of underlying conditions, including endometriosis, uterine
fibroids, adenomyosis, pelvic inflammatory disease,
adhesions, and use of an IUD.
These conditions should first be diagnosed prior to recommending
If you experience changes in your menstrual
cramps, such as severity, timing, or location, consult with your doctor,
particularly if these changes come on suddenly.
What's the prognosis for menstrual cramps?
Generally speaking, a woman's menstrual cramps don't worsen throughout
her lifetime. The cramps of primary dysmenorrhea usually subside with
age and pregnancy. In the case of secondary dysmenorrhea, where an underlying
gynecologic condition contributes to pain, the prognosis depends on successful
treatment of that condition.