Up to 85% of women normally have one or more troubling physical and emotional symptoms, including menstrual cramps, between the time they ovulate and the first days of their menstrual period.1 These are called premenstrual symptoms. When premenstrual symptoms interfere with your relationships or responsibilities, they are called Premenstrual Syndrome (PMS).
PMS consists of a wide variety of physical, emotional and behavioural symptoms - including abdominal cramps, or dysmenorrhoea - which vary greatly from woman to woman and range from mild to severe. PMS symptoms are linked to changes in the endocrine system, which produces hormones that control the menstrual cycle.
Because the female endocrine system is so complex, medical experts don't fully understand the chain of events that causes PMS to be severe in some women and not in others. Many women with PMS have a close family member with a history of PMS.2 Moreover, PMS occurs only in women who ovulate during their monthly menstrual cycle. Women who do not ovulate - because of pregnancy, menopause or taking birth control pills - do not have PMS symptoms, like menstrual cramps.
References
1 PAMF.org HealthWise KnowledgeBase, Premenstrual Syndrome (PMS), Palo Alto Medical Foundation, 2004.
2 Dickerson, LM et al, "Premenstrual syndrome," American Family Physician, 76(8): 1743-1752, 2003.
