- Menstrual cramps facts
- What are menstrual cramps?
- How common are menstrual cramps?
- What is dysmenorrhea?
- What causes menstrual cramps?
- Why are some cramps so painful?
- Can menstrual cramps be measured?
- What other factors influence menstrual cramps?
- What are the symptoms of menstrual cramps?
- How are menstrual cramps diagnosed?
- What is the treatment for common menstrual cramps (primary dysmenorrhea)?
- What if the cramps are very severe?
- Are there surgical solutions?
- What is the treatment of secondary dysmenorrhea?
- What is the long-term outlook (prognosis) for menstrual cramps?
Menstrual cramps facts
- Menstrual cramps are periodic abdominal and pelvic pains experienced by women.
- More than half of all menstruating women have cramps.
- The cramps are severe in at least one in four of these women.
- Medically, menstrual cramps are called dysmenorrhea.
- Primary dysmenorrhea is common menstrual cramps without an identifiable cause.
- Secondary dysmenorrhea results from an underlying abnormality that usually involves the woman's reproductive system.
- Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat cramps.
- Physical exercise can help alleviate menstrual cramps.
- Menstrual cramps tend to improve with age.
What are menstrual cramps?
Menstrual cramps are pains in the abdomen and pelvic areas that can be experienced by a woman as a result of her menstrual period. Menstrual cramps are not the same as the discomfort felt duringpremenstrual syndrome (PMS), although the symptoms of both disorders can sometimes be experienced as a continuous process. Many women suffer from both PMS and menstrual cramps.
Menstrual cramps can range from mild to quite severe. Mild menstrual cramps may be barely noticeable and of short duration. They are sometimes felt as just a sense of heaviness in the abdomen. Severe menstrual cramps can be so painful that they interfere with a woman's normal activities for several days.
What is dysmenorrhea?
The medical term for painful menstrual periods is dysmenorrhea. There are two types of dysmenorrhea: primary and secondary.
In primary dysmenorrhea there is no underlying gynecologic pathology causing the pain. This type of cramping may begin within six months to a year following menarche (the beginning of menstruation). Menstrual cramps typically are not experienced until ovulatory menstrual cycles (when an egg is released from the ovaries) begin. Menstrual bleeding usually begins before the onset of monthly ovulation. Therefore, an adolescent girl may not experience dysmenorrhea until months to years following the onset of menstruation.
In secondary dysmenorrhea, some underlying abnormal condition (usually involving the woman's reproductive system) contributes to the menstrual pain. Secondary dysmenorrhea may be evident at menarche, but more often, the condition develops later.
What causes menstrual cramps?
Each month, the inner lining of the uterus (the endometrium) normally builds up in preparation for a possible pregnancy. After ovulation, if the egg is not fertilized by a sperm, no pregnancy will result and the current lining of the uterus is no longer needed. The woman's estrogen and progesterone hormone levels decline, and the lining of the uterus becomes swollen and is eventually shed as the menstrual flow. It is replaced by a new growth of lining during the next monthly cycle.
When the uterine lining begins to break down, molecular compounds called prostaglandins are released. These compounds cause the muscles of the uterus to contract. When the uterine muscles contract, they constrict the blood supply (vasoconstriction) to the endometrium. This contraction blocks the delivery of oxygen to the tissue of the endometrium which, in turn, breaks down and dies. After the death of this tissue, the uterine contractions squeeze the old endometrial tissue through the cervix and out of the body by way of the vagina. Other substances known as leukotrienes, which are chemicals that play a role in the inflammatory response, are also elevated at this time and may be related to the development of menstrual cramps.
Why are some cramps so painful?
Menstrual cramps are caused by the uterine contractions that occur in response to prostaglandins and other chemicals. The cramping sensation 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 difference between menstrual cramps that are more painful and those that are less painful may be related to a woman's prostaglandin levels. Women with menstrual cramps have elevated levels of prostaglandins in the endometrium (uterine lining) when compared with women who do not experience cramps. Menstrual cramps are very similar to those a pregnant woman experiences when she is given prostaglandins as medication to induce labor.
Can menstrual cramps be measured?
Yes, but measuring the strength of menstrual cramps is not routinely done in clinical practice. Researchers have demonstrated that menstrual cramps can be scientifically documented by measuring the pressure within the uterus, as well as the number and frequency of uterine contractions. During a normal menstrual period, the average woman has contractions of a low pressure (50-80 mm Hg), which last 15-30 seconds at a frequency of 1-4 contractions every 10 minutes. When a woman with dysmonorrhea has menstrual cramps, her contractions are usually of a higher pressure (they may exceed 400 mm Hg), last longer than 90 seconds, and often occur less than 15 seconds apart.
What other factors influence menstrual cramps?
- As mentioned above, an unusually narrow cervical canal tends to increase menstrual cramps.
- Another anatomical factor that may contribute to menstrual cramps is a retroverted uterus (the uterus tilts backward instead of forward).
- Lack of exercise is now recognized to contribute to painful menstrual cramps, because exercise releases endorphins that relieve pain.
- It has long been thought that psychological factors also play a role. For example, it is widely accepted that emotional stress can increase the discomfort of menstrual cramps.
- Adenomyosis and endometriosis can increase the severity of menstrual cramps
- Having uterine fibroids can worsen menstrual cramping
What are the symptoms of menstrual cramps?
Menstrual cramps are pains that begin in the lower abdomen and pelvis. The discomfort can extend to the lower back or legs. The cramps can be a quite painful or simply a dull ache. They can be periodic or continuous. Pain also may be felt in the inner thighs, or hips.
Menstrual cramps usually begin before the onset of menstrual period, peak within 24 hours after the onset of the bleeding, and subside again after a day or two.
Menstrual cramps may be accompanied by a headache and/or nausea, which can lead, although infrequently, to vomiting. Menstrual cramps can also be accompanied by either constipation or diarrhea, because the prostaglandins which cause smooth muscles to contract also affect the intestinal tract. Some women experience an urge to urinate more frequently.
How are menstrual cramps diagnosed?
The diagnosis of menstrual cramps is usually made by the woman herself and reflects her individual perception of pain. Once a woman has experienced menstrual cramps, usually with the adolescent onset of her monthly menstrual flow (menses), she becomes well aware of the typical symptoms. If there are other medical conditions contributing to menstrual cramps (secondary dysmenorrhea), the doctor may suggest diagnostic testing including imaging studies.
What is the treatment for common menstrual cramps (primary dysmenorrhea)?
Every woman needs to find a treatment that works for her. There are a number of possible remedies for menstrual cramps.
Current recommendations include not only adequate rest and sleep, but also regular exercise (especially walking). Some women find that abdominal massage, yoga, or orgasmic sexual activity may bring relief. A heating pad applied to the abdominal area may relieve the pain and congestion.
A number of nonprescription (over-the-counter) agents can help control the pain as well as actually prevent the menstrual cramps altogether. For mild cramps, aspirin, acetaminophen (Tylenol), or acetaminophen plus a diuretic (Diurex MPR, FEM-1, Midol, Pamprin, Premsyn, and others) may be sufficient. However, aspirin has limited effect in curbing the production of prostaglandin, and it is only useful for less painful cramps.
The main agents for treating moderate menstrual cramps are the nonsteroidal antiinflammatory drugs (NSAIDs) which lower the production of prostaglandin and lessen its effect. The NSAIDs that do not require a prescription are:
- ibuprofen (Advil, Midol IB, Motrin, Nuprin, and others);
- naproxen sodium (Aleve, Anaprox); and
- ketoprofen (Actron, Orudis KT).
A woman should start taking one of these medications before her pain becomes difficult to control. This might mean starting medication 1 to 2 days before her anticipated period is due, and then continuing taking the medication for the first one to two days of her period. The best results are obtained by taking one of the NSAIDs on a scheduled basis and not waiting for the pain to begin.
Prescription NSAIDs available for the treatment of menstrual cramps include mefenamic acid (Ponstel) and meclofenamate (Meclomen).
What if the cramps are very severe?
If a woman's menstrual cramps are too severe to be managed by these strategies, her doctor might prescribe low doses of birth control pills (oral contraceptives) containing estrogen and progestin in a regular or extended cycle. This type of approach can prevent ovulation (the monthly release of an egg) and reduce the production of prostaglandins which, in turn, reduces the severity of cramping.
Use of an IUD that releases small amounts of the progestin levonorgestrel directly into the uterine cavity, has been associated with a 50 percent reduction in the prevalence of menstrual cramps. In contrast, IUDs that do not contain hormones, such as those containing copper, may worsen menstrual cramps.
Are there surgical solutions?
In the past, many women with menstrual cramps had an operation known as a D & C (dilation and curettage) to remove some of the lining of the uterus. This procedure is also sometimes used as a diagnostic measure to detect cancer or precancerous conditions of the uterine lining. Some women even resorted to the ultimate solution to menstrual problems by having a hysterectomy, a surgical procedure in which the entire uterus is removed.
Today, when a woman has abnormally heavy and painful uterine bleeding, her doctor may recommend endometrial ablation, a procedure in which the lining of the uterus is destroyed by various devices.
What is the treatment of secondary dysmenorrhea?
The treatment of secondary dysmenorrhea depends on its cause. There are a number of underlying conditions which can contribute to the pain including:
- Endometriosis (cells from the uterine lining are located in other areas of the body outside of the uterus)
- Uterine fibroids (non-cancerous uterine growths that respond to estrogen levels)
- Adenomyosis (a benign condition in which the cells of the inner uterine lining invade its muscular wall, the myometrium)
- Pelvic inflammatory disease (PID)
- Adhesions (abnormal fibrous attachments between organs)
- Use of a copper intrauterine device (IUD) for contraception.
All of these conditions should be first diagnosed by a physician who will then recommend the optimal treatment.
If a woman begins to experience changes in her menstrual cramps, such as in their severity, timing, or location, she should consult her physician, especially if the changes are of sudden onset.
What is the long-term outlook (prognosis) for menstrual cramps?
In general, a woman's menstrual cramps do not worsen during her lifetime. In fact, the menstrual cramps of primary dysmenorrhea usually diminish with age and after pregnancy.
When there is secondary dysmenorrhea with an underlying condition contributing to the pain, the prognosis depends on the successful treatment of that underlying condition.
As women have learned more about their bodies and how to maintain them in optimal health, menstrual cramps have become less debilitating, and more often, merely a minor monthly inconvenience.
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Medically reviewed by Wayne Blocker, MD; Board Certified Obstetrics and Gynecology