Premenstrual dysphoric disorder (PMDD) can be considered a severe form of premenstrual syndrome (PMS). Both PMS and PMDD are characterized by unpleasant physical and psychological symptoms that occur in the second half of a woman's menstrual cycle, most commonly in the days preceding the menstrual period. Physical symptoms such as bloating, breast tenderness, headaches, joint pain, food cravings, mood swings or frequent crying, panic attacks, fatigue, mood changes, irritability, and trouble focusing are among the most common symptoms. Other symptoms like anxiety and trouble sleeping have been reported. PMS symptoms may be troubling and unpleasant. PMDD may cause severe, debilitating symptoms that interfere with a woman's ability to function.

The American College of Obstetricians and Gynecologists estimates that at least 85 percent of menstruating women have at least one PMS symptom as part of their monthly cycle. PMS is much more common than PMDD. You must have 5 or more of the symptoms listed above to be diagnosed with PMDD.

Biologic, psychological, environmental, and social factors all seem to play a part in PMDD. It is important to note that PMDD is not the fault of the woman suffering from it or the result of a "weak" or unstable personality. It is also not something that is "all in the woman's head." Rather, PMDD is a medical illness that impacts only 3% to 8% of women. Fortunately, it can be treated by a health care professional with behavioral and pharmaceutical options.