Abnormalities of the Menstrual Cycle 

Dysmenorrhea is defined as pain and cramping during menstruation that interferes with normal activities and requires over-the-counter or prescription medication. Mild pain during menses is normal. Discomfor during menstruation ranges from mild discomfort to severe pain that causes some patients to be bedridden. Fifty percent of menstruating women suffer from dysmenorrhea and 10% of these are incapacitated for 1 to 3 days each month.

Dysmenorrhea is clssified as primary or secondary. Primary dysmenorrhea is idiopathic menstrual pain without identifiable pathology; secondary dysmenorrhea is painful menses due to underlying pathology ( endometriosis, fibroids, adenomyosis, PID, cervical stenosis).

Premenstrual Syndrome and Premenstrual Dysphoric Disorder

premenstrual syndrome (PMS) and its more severe variant, premenstrual dysphoric disorder (PMDD) are characterized by is a constellation of physical and/or behavioral changes that occur in the second half of the menstrual cycle. These changes might include headache, weight gain, bloating, breast tenderness, mood fluctuation, restlessness, irritability, anxiety, depression, fatigue, and a feeling of being out of control. These symptoms must occur in the 2 weeks prior to menstruation and there must be at least a 7-day sympton-free interval in the first half of the menstrual cycle. Symptoms must occur in at least two consecutive cycle. Symptoms must occur in at least two consecutive cycles for the diagnosis to be made.

some 75% of women suffer from some recurrent PMS symptoms; of these, 30% report significant problems and 5% of women are incapacitated or severely distressed by PMDD at some point during their cycle. The highest incidence occurs among women in their late 20s to early 30s.

Pathogenesis

The exact etiology of PMS and PMDD is unknown but is likely multifactorial and includes both physiologic and psychological causes. Past hypothese have included abnormalities in estrogen-progesterone balance, disturbance in the renin-angiotensin-aldosterone pathway, excess prostaglandin and prolactin production, and psychogenic factors. Recent studies also suggest that PMS and PMDD may be due to the interaction between the neurotransmitter serotonin and cyclic changes in the ovarian steroids. the serum concentrations of estrogen and progessterone are no different in patients with PMS/PMDD and those withour. However, studies have suggested that although women with PMS and PMDD have normal levels of estrogen and progesterone, they may have an abnormal response tonormal hormonal changes.

Abnormal Uterine Bleeding

The normal menstrual cycle consists of cyclic bleeding approximately every 28 days (normal range, 21 to 35 days), lasting 3 to 5 days with about 30 to 50mLof blood loss per cycle. Abnormal uterine bleeding refers to any departure from the norm in the menstrual cycle. it can involve too much bleeding (heavy periods, frequent menses, or bleeding between periods) or too little bleeding ( light periods, infrequent periods, or complete absence of periods). 

Dysfunctional Uterine Bleeding

If no pathologic cause of abnormal uterine bleeding is identified, the diagnosis of dysfunctional uterine bleeding (DUB) is made. DUB is a diagnosis of exclusion. Most patients with DUB are anovulatory. In these instances, the ovary produces estrogen but no corpus luteum is formed, and thus no progesterone is produced. Subsequently, there is continuous estrogenic stimulation of the endometrium without the usual progesterone-induced bleeding. Instead, in DUB, the endometrium continues to proliferate until it outgrows it blood supply, breaks down, and sloughs off in an irregular fashion. DUB is most likely to occur with anovulatory cycles and thus is most common during times in a woman's life when she is most likely to be anovulatory such as adolescence, perimenopause, lactation, and prenancy. Pathologic anovulation occurs in hypothroidism, hyperprolactinemia, hyperandrogenism, and PMOF.

Postmenopausal Bleeding

menopause is marked by 12 months of amenorrhea after the final menstrual period. Postmenopausal bleeding, then, is any vaginal bleeding that occurs more than 12 months after the last menstrual period. Any postmenopausal bleeding is abnormal and should be invesigated given the increased risk of reproductive cancers in women in this age group. The most common cause of postmenopausal bleeding, however, is endometrial and /or vaginal atrophy, not cancer. Endometrial cancer in responsible for only 10% to 15% of all postmenopausal bleeding.