Oligomenorrhea is infrequent (or, in occasional usage, very light)

menstruation Menstruation (also known as a period, among other colloquial terms) is the regular discharge of blood and mucosal tissue from the inner lining of the uterus through the vagina. The menstrual cycle is characterized by the rise and fall of hor ...

. More strictly, it is menstrual periods occurring at intervals of greater than 35 days, with only four to nine periods in a year.thefreedictionary.com > oligomenorrhea
This dictionary is citing Gale Encyclopedia of Medicine. 2008 Menstrual periods should have been regularly established before the development of infrequent flow. The duration of such events may vary.

Causes

Oligomenorrhea can be a result of prolactinomas (

adenomas An adenoma is a benign tumor of epithelial tissue with glandular origin, glandular characteristics, or both. Adenomas can grow from many glandular organs, including the adrenal glands, pituitary gland, thyroid, prostate, and others. Some adeno ...

of the anterior

pituitary In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The hypop ...

). It may be caused by

thyrotoxicosis Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism. ...

, hormonal changes in

perimenopause Menopause, also known as the climacteric, is the time in women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between the age of 47 and 54. Medical professionals often d ...

Prader–Willi syndrome Prader–Willi syndrome (PWS) is a genetic disorder caused by a loss of function of specific genes on chromosome 15. In newborns, symptoms include weak muscles, poor feeding, and slow development. Beginning in childhood, those affected become ...

, and

Graves disease Graves' disease (german: Morbus Basedow), also known as toxic diffuse goiter, is an autoimmune disease that affects the thyroid. It frequently results in and is the most common cause of hyperthyroidism. It also often results in an enlarged thyro ...

. Endurance exercises such as running or swimming can affect the reproductive physiology of female athletes. Female runners, swimmers and ballet dancers either menstruate infrequently in comparison to non-athletic females of comparable age or exhibit

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). Outside the reproductive years, there is absence of menses ...

. A more recent study shows that athletes competing in sports that emphasise thinness or a specific weight exhibit a higher rate of menstrual dysfunction than either athletes competing in sports with less focus on these or control subjects. Breastfeeding has been linked to irregularity of menstrual cycles due to hormones that delay ovulation. People with

polycystic ovary syndrome Polycystic ovary syndrome, or PCOS, is the most common endocrine disorder in women of reproductive age. The syndrome is named after the characteristic cysts which may form on the ovaries, though it is important to note that this is a sign and no ...

(PCOS) are also likely to have oligomenorrhea. PCOS is a condition in which excessive

androgens An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...

(male sex hormones) are released by the

ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...

. People with PCOS show menstrual irregularities that range from oligomenorrhea and amenorrhea, to very heavy, irregular periods. The condition affects about 6% of premenopausal females. Eating disorders can result in oligomenorrhea. Although menstrual disorders are most strongly associated with

anorexia nervosa Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by low weight, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. ''Anorexia'' is a term of Gr ...

bulimia nervosa Bulimia nervosa, also known as simply bulimia, is an eating disorder characterized by binge eating followed by purging or fasting, and excessive concern with body shape and weight. The aim of this activity is to expel the body of calories eaten ...

may also result in oligomenorrhea or amenorrhea. There is some controversy regarding the mechanism for the menstrual dysregulation, since amenorrhea may sometimes precede substantial weight loss in some anorexics.

References

External links

{{Menstrual cycle Menstrual disorders

Causes

See also

References

External links