Amenorrhea

Amenorrhea is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding), the latter also forming the basis of a form of contraception known as the lactational amenorrhoea method. Outside the reproductive years, there is absence of menses during childhood and after menopause. Amenorrhea is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen, most commonly, during pregnancy and lactation (breastfeeding), the latter also forming the basis of a form of contraception known as the lactational amenorrhoea method. Outside the reproductive years, there is absence of menses during childhood and after menopause. Amenorrhoea is a symptom with many potential causes.Primary amenorrhoea is defined as an absence of secondary sexual characteristics by age 14 with no menarche or normal secondary sexual characteristics but no menarche by 16 years of age. It may be caused by developmental problems, such as the congenital absence of the uterus, failure of the ovary to receive or maintain egg cells, or delay in pubertal development.Secondary amenorrhoea (menstrual cycles ceasing) is often caused by hormonal disturbances from the hypothalamus and the pituitary gland, from premature menopause or intrauterine scar formation. It is defined as the absence of menses for three months in a woman with previously normal menstruation, or nine months for women with a history of oligomenorrhoea. There are two primary ways to classify amenorrhoea. Types of amenorrhoea are classified as primary or secondary, or based on functional 'compartments'. The latter classification relates to the hormonal state of the patient that hypo-, eu-, or hypergonadotropic (whereby interruption to the communication between gonads and follicle stimulating hormone (FSH) causes FSH levels to be either low, normal or high). Women who perform considerable amounts of exercise on a regular basis or lose a significant amount of weight are at risk of developing hypothalamic (or 'athletic') amenorrhoea. Functional Hypothalamic Amenorrhoea (FHA) can be caused by stress, weight loss, and/or excessive exercise. Many women who diet or who exercise at a high level do not take in enough calories to expend on their exercise as well as to maintain their normal menstrual cycles. The threshold of developing amenorrhoea appears to be dependent on low energy availability rather than absolute weight because a critical minimum amount of stored, easily mobilized energy is necessary to maintain regular menstrual cycles. Energy imbalance and weight loss can disrupt menstrual cycles through several hormonal mechanisms. Weight loss can cause elevations in the hormone ghrelin which inhibits the hypothalamic-pituitary-ovarial axis. Elevated concentrations of ghrelin alter the amplitude of GnRH pulses, which causes diminished pituitary release of LH and follicle-stimulating hormone (FSH). Secondary amenorrhea is caused by low levels of the hormone leptin in females with low body weight. Like ghrelin, leptin signals energy balance and fat stores to the reproductive axis. Decreased levels of leptin are closely related to low levels of body fat, and correlate with a slowing of GnRH pulsing.When a woman is experiencing amenorrhoea, an eating disorder, and osteoporosis together, this is called female athlete triad syndrome. A lack of eating causes amenorrhoea and bone loss leading to osteopenia and sometimes progressing to osteoporosis. The social effects of amenorrhoea on a person vary significantly. Amenorrhoea is often associated with anorexia nervosa and other eating disorders, which have their own effects. If secondary amenorrhoea is triggered early in life, for example through excessive exercise or weight loss, menarche may not return later in life. A woman in this situation may be unable to become pregnant, even with the help of drugs. Long-term amenorrhoea leads to an estrogen deficiency which can bring about menopause at an early age. The hormone estrogen plays a significant role in regulating calcium loss after ages 25–30. When her ovaries no longer produce estrogen because of amenorrhoea, a woman is more likely to suffer rapid calcium loss, which in turn can lead to osteoporosis. Increased testosterone levels cause by amenorrhoea may lead to body hair growth and decreased breast size. Increased levels of androgens, especially testosterone, can also lead to ovarian cysts. Some research among amenorrhoeic runners indicates that the loss of menses may be accompanied by a loss of self-esteem. Certain medications, particularly contraceptive medications, can induce amenorrhoea in a healthy woman. The lack of menstruation usually begins shortly after beginning the medication and can take up to a year to resume after stopping a medication. Hormonal contraceptives that contain only progestogen like the oral contraceptive Micronor, and especially higher-dose formulations like the injectable Depo Provera commonly induce this side effect. Extended cycle use of combined hormonal contraceptives also allow suppression of menstruation. Patients who use and then cease using contraceptives like the combined oral contraceptive pill (COCP) may experience secondary amenorrhoea as a withdrawal symptom. The link is not well understood, as studies have found no difference in hormone levels between women who develop amenorrhoea as a withdrawal symptom following the cessation of COCP use and women who experience secondary amenorrhoea because of other reasons. New contraceptive pills, like continuous oral contraceptive pills (OCPs) which do not have the normal 7 days of placebo pills in each cycle, have been shown to increase rates of amenorrhoea in women. Studies show that women are most likely to experience amenorrhoea after 1 year of treatment with continuous OCP use. The use of opiates (such as heroin) on a regular basis has also been known to cause amenorrhoea in longer term users.