Most women have painful menstrual cramps (dysmenorrhea) from time to time. Menstrual cramps are one of the most common reasons for women to seek medical attention. The pain from menstrual cramps can range from mild to severe and can involve the lower abdomen, back, or thighs. You may also have headaches, nausea, dizziness or fainting, or diarrhea or constipation with your cramps.

During the menstrual cycle, the lining of the uterus produces a hormone called prostaglandin. This hormone causes the uterus to contract, often painfully. Women with severe cramps may produce higher-than-normal amounts of prostaglandin, or they may be more sensitive to its effects.

Cramping is common during the teen years, when a woman first starts having periods. Primary dysmenorrhea is a term used to describe painful menstrual cramping with no recognized physical cause. It is seen most commonly in women between the ages of 20 and 24. It usually goes away after 1 to 2 years, when hormonal balance occurs.

Secondary dysmenorrhea is a term used to describe painful menstrual cramping caused by a physical problem other than menstruation. Physical problems that can cause this type of cramping include:

• A condition in which cells that look and act like the cells of the lining of the uterus (endometrium) are found in other parts of the abdominal cavity (endometriosis) or grow into the muscular tissue of the uterine wall (adenomyosis). Pain usually occurs 1 to 2 days before menstrual bleeding begins and continues through the period.
• Growths that are not cancerous (benign growths) in the pelvis, such as ovarian cysts, cervical or uterine polyps, or fibroids.
• Pelvic infections. Your risk for developing an infection is higher after menstrual bleeding has begun because the opening to the uterus (cervical canal) widens during menstruation. You may have a fever with an infection. But pelvic infections, especially those caused by sexually transmitted diseases (STDs), can occur at any time.
• Using an intrauterine device (IUD). An IUD may cause increased cramping during your period for the first few months of use. If menstrual cramping persists or gets worse, you may need to consider having the IUD removed and choosing another birth control method.
• Problems with the pregnancy.
• Structural problems that were present at birth (congenital), such as narrowing of the lower part of the uterus that opens into the vagina (cervix).

Menstrual-type cramps may occur after a medical procedure, such as cautery, cryotherapy, conization, radiation, endometrial biopsy, or IUD insertion.

Other menstrual symptoms, such as weight gain, headache, and tension, that occur before your period begins can be caused by premenstrual syndrome (PMS). For more information, see the topic Premenstrual Syndrome (PMS).

Review the Check Your Symptoms section to determine if and when you need to see your doctor.