Menstrual cramps are pains in the lowest part of the abdomen (pelvis), a few days before, during, or after a menstrual period. The pain tends to be most intense about 24 hours after periods begin and to subside after 2 to 3 days. The pain is often crampy or a dull, constant ache, but it may be sharp or throbbing and may come and go. It sometimes extends to the lower back or legs.
Many women also have a headache, nausea (sometimes with vomiting), and constipation or diarrhea. They may need to urinate frequently.
Some women with painful periods also have symptoms of premenstrual syndrome (such as irritability, nervousness, depression, fatigue, and abdominal bloating). These symptoms may persist during part or all of the menstrual period.
Sometimes menstrual blood contains clots. The clots, which may appear bright red or dark, may contain tissue and fluid from the lining of the uterus, as well as blood.
Symptoms tend to be more severe if
Menstrual periods started at an early age.
Periods are long or heavy.
Women smoke.
Family members also have dysmenorrhea.
Symptoms tend to lessen after women have their first pregnancy and as they get older.
Causes of Menstrual Cramps
Menstrual cramps may
Have no identifiable cause (called primary dysmenorrhea)
Result from another disorder (called secondary dysmenorrhea)
Primary dysmenorrhea usually starts during adolescence and may become less severe with age and after pregnancy. It is more common than secondary dysmenorrhea.
Secondary dysmenorrhea usually starts during adulthood (unless it is caused by a birth defect of the reproductive system).
Common causes
More than 50% of women with dysmenorrhea have primary dysmenorrhea. In about 5 to 15% of these women, cramps are severe enough to interfere with daily activities and may cause them to miss school or work.
Experts think that primary dysmenorrhea may be caused by release of substances called prostaglandins into the blood or tissues during menstruation. Prostaglandin levels are high in women with primary dysmenorrhea. Prostaglandins may cause the uterus to contract (as occurs during labor), reducing blood flow to the uterus. These contractions can cause pain and discomfort. Prostaglandins also make nerve endings in the uterus more sensitive to pain.
Anxiety may also contribute to the pain.
Secondary dysmenorrhea is caused by abnormalities in the reproductive system. It is commonly caused by
Endometriosis: Tissue that normally occurs only in the lining of the uterus (endometrial tissue) appears outside the uterus. Endometriosis is the most common cause of secondary dysmenorrhea.
Adenomyosis: Endometrial tissue grows into the wall of the uterus, causing it to enlarge and swell during menstrual periods.
Fibroids: These noncancerous tumors are composed of muscle and fibrous tissue and grow in the uterus.
Less common causes
There are many less common causes of secondary dysmenorrhea. They include
Cysts and tumors in the ovaries
Use of an intrauterine device (IUD)
Scar tissue in the uterus
progesterone) usually do not cause painful periods.
In a few women, pain occurs because the passageway through the cervix (cervical canal) is narrow. A narrow cervical canal (cervical stenosis) may develop after a procedure, as when a precancerous condition (dysplasia) of the cervix is treated.
Evaluation of Menstrual Cramps
Doctors usually diagnose dysmenorrhea when a woman reports that she regularly has bothersome pain during menstrual periods. They then determine whether dysmenorrhea is primary or secondary.
Warning signs
In women with dysmenorrhea, certain symptoms are cause for concern:
Severe pain that began suddenly or is new
Constant pain
Fever
A pus-like discharge from the vagina
Sharp pain that worsens when the abdomen is touched gently or the person moves even slightly
When to see a doctor
Women with any warning sign should see a doctor as soon as possible (usually the same day).
If women without warning signs have more severe cramps than usual or have pain that lasts longer than usual, they should see a doctor within a few days.
Other women who have menstrual cramps should call their doctor. The doctor can decide how quickly they need to be seen based on their other symptoms, age, and medical history.
What the doctor does
Doctors or other health care practitioners ask about the pain and the medical history, including the menstrual history. Practitioners then do a physical examination. What they find during the history and physical examination may suggest a cause of menstrual cramps and the tests that may need to be done (see table Some Causes and Features of Menstrual Cramps).
For a complete menstrual history, practitioners ask a woman
How old she was when menstrual periods started
How many days they last
How heavy they are
How long the interval between periods is
Whether periods are regular
Whether spotting occurs between periods
When symptoms occur in relation to periods
Practitioners also ask the woman the following:
How old she was when menstrual cramps began
What other symptoms she has
What the pain is like, including how severe it is, what relieves or worsens symptoms, and how symptoms interfere with her daily activities
Whether she has pelvic pain unrelated to periods
Whether nonsteroidal anti-inflammatory drugs (NSAIDs) help relieve the pain
Whether she has pain during sexual activity or has had problems becoming pregnancy (as may occur in endometriosis)
The woman is asked whether she has or has had disorders and other conditions that can cause cramps, including use of certain drugs (such as birth control pills) or an IUD. Practitioners ask whether she has had any surgical procedures that increase the risk of pelvic pain, such as a procedure that destroys or removes the lining of the uterus (endometrial ablation).
A pelvic examination is done. Doctors check for abnormalities, including discharge, tenderness, polyps, and fibroids.
Doctors also gently feel the abdomen to check for areas of particular tenderness, which may indicate severe inflammation in the abdomen (peritonitis).
Testing
Testing is done to rule out disorders that may be causing the pain. For most women, tests include
A pregnancy test in all women of reproductive age
Ultrasonography of the pelvis to check for fibroids, endometriosis, adenomyosis, and cysts in the ovaries
If pelvic inflammatory disease is suspected, a sample of secretions is taken from the cervix, examined under a microscope, and sent to a laboratory to be tested.
If results of these tests are unclear and symptoms persist, one or more of the following tests is done:
Imaging tests such as hysterosalpingography or sonohysterography to identify polyps, fibroids, and birth defects
Hysteroscopy to identify problems with the cervix or uterus (but not with the ovaries)
Magnetic resonance imaging (MRI) to identify other abnormalities
Laparoscopy if results of other tests are unclear
For hysterosalpingography, x-rays are taken after a substance that can be seen on x-rays (radiopaque contrast agent) is injected through the cervix into the uterus and fallopian tubes. If results are unclear, magnetic resonance imaging (MRI) may be done.
For sonohysterography, ultrasonography is done after fluid is infused in the uterus through a thin tube inserted through the vagina and cervix. The fluid makes abnormalities easier to identity.
For hysteroscopy, doctors insert a thin viewing tube through the vagina and cervix to view the interior of the uterus. This procedure can be done in a doctor's office or in a hospital as an outpatient procedure.
For laparoscopy, a viewing tube is inserted through a small incision just below the navel and is used to view the uterus, fallopian tubes, ovaries, and organs in the abdomen. This procedure is done in a hospital or surgical center. Laparoscopy enables doctors to directly view structures in the pelvis.
Treatment of Menstrual Cramps
Nonsteroidal anti-inflammatory drugs (NSAIDs)
Often hormonal contraceptives
Treatment of underlying disorders
When menstrual cramps result from another disorder, that disorder is treated if possible. For example, a narrow cervical canal can be widened surgically. However, this operation usually relieves the pain only temporarily. If needed, fibroids or misplaced endometrial tissue (due to endometriosis) is surgically removed.
If women have primary dysmenorrhea do not have a specific disorder that can be treated, they may use general measures or NSAIDs to relieve symptoms.
General measures
Moist heat applied to the abdomen may help.
Getting enough sleep and rest and exercising regularly may also help.
Medications
If NSAIDs are ineffective, doctors may recommend also taking birth control pills that contain a progestin (a synthetic form of the female hormone progesterone) and estrogen. These pills prevent the ovaries from releasing an egg (ovulation). Women who cannot take estrogen can take birth control pills that contain only a progestin.
Other treatments
If a woman may have endometriosis and medications have not worked or if she has infertility, doctors may do laparoscopic surgery to confirm the diagnosis of endometriosis and remove endometrial tissue (tissue from the lining of the uterus) that is located outside the uterus.
If women have severe pain that persists despite all other types treatment, doctors may do a procedure that disrupts the nerves to the uterus and thus blocks pain signals. These procedures include the following:
Injecting the nerves with an anesthetic (a nerve block)
Destroying the nerves using a laser, electricity, or ultrasound
Cutting the nerves
The procedures to disrupt the nerves may be done using a laparoscope. When these nerves are cut, other organs in the pelvis, such as the ureters, are occasionally injured.
Some alternative treatments for menstrual cramps have been suggested but have not been studied well. They include behavioral counseling (such as systematic desensitization and relaxation and pain management training), acupuncture, and acupressure. Hypnosis is being studied as treatment.
Key Points
Usually, menstrual cramps have no identifiable cause (called primary dysmenorrhea).
Pain is often crampy or a dull, constant ache but may be or sharp or throbbing and usually starts a few days before a menstrual period, and subsides after 2 or 3 days.
For most women, evaluation includes a pregnancy test, a doctor's examination, and ultrasonography (to check for abnormal structures or growths in the pelvis).
For primary dysmenorrhea, general measures, such as adequate sleep, regular exercise, and heat may help relieve symptoms.
NSAIDs or an NSAID plus birth control pills that contain a progestin and estrogen may help relieve the pain.
