Dysmenorrhea (dis-men-oh-REE-uh) is pain a woman feels during menstruation (men-strew-ay-shun). Discomfort is primarily caused by cramping of the uterus, due to unusually high levels of substances called prostaglandins (PROSS-ta-glan-dinz). The most common type is primary dysmenorrhea, which is an extreme form of discomfort most women feel just before or on the first few days of their period. Pain may be accompanied by nausea, vomiting, chills, and diarrhea. Applying heat to the lower abdomen may help ease discomfort. Most women respond to non-steroidal anti-inflammatory drugs, or 'N-SAIDs,' (in saids) many of which are available over the counter. However, they should be taken before cramps start, or at the first sign of bleeding. Doctors may also prescribe medications that inhibit the formation of prostaglandins. Dysmenorrhea is more common in women who've never had children. The symptoms tend to decrease with age and after a full-term pregnancy. Secondary dysmenorrhea usually occurs suddenly in women whose early menstrual periods have been relatively pain-free. An underlying medical problem such as endometriosis (en-doe-mee-tree-OH-sis) or pelvic inflammatory disease may be the cause. Pain can begin two or three days before the menstrual period, and radiate from the abdomen to the back and legs, lasting throughout the period. If you have painful menstrual periods, you may want to seek medical attention, especially to rule out other problems. Your doctor can prescribe medications or recommend other measures that may ease your pain. For more information, contact your health care professional.