In medicine, anovulation is absence of ovulation when it would be normally expected (in a post-menarchal, premenopausal woman). Anovulation can result from a variety of factors: The following codes are used with International Statistical Classification of Diseases and Related Health Problems. ... The International Classification of Diseases for Oncology (ICD-O) is a domain specific extension of the International Statistical Classification of Diseases and Related Health Problems for tumor diseases. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... MedlinePlus (medlineplus. ... eMedicine is an online clinical medical knowledge base that was founded in 1996. ... The Diseases Database is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... Ovulation is the process in the menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum (also known as an oocyte, female gamete, or casually, an egg) that participates in reproduction. ... Menarche refers to the first menstrual period, or first menstrual bleeding, as a girls body progresses through the changes of puberty. ...

• Stress, new environment
• Chronic mental illness, such as depression
• Chronic physical illness, such as inflammatory bowel disease, poorly controlled diabetes, tuberculosis, or anemia
• Undernutrition, specific nutrient deficiencies, inadequate body fat
• Prolonged or continuous physical exertion
• Various pharmaceutical (especially phenothiazines) and recreational drugs
• Hormone imbalances, such as prolactin or testosterone excess (e.g., polycystic ovary syndrome), hyper- or hypothyroidism, adrenal insufficiency or Cushing's syndrome.
• Pituitary or ovarian failure.

Some anovulatory women may have two or more contributing conditions. Anovulation can generally be reversed by ameliorating the causal factors (except in cases of permanent pituitary or ovarian failure). Stress (roughly the opposite of relaxation) is a medical term for a wide range of strong external stimuli, both physiological and psychological, which can cause a physiological response called the general adaptation syndrome, first described in 1936 by Hans Selye in the journal Nature. ... Clinical depression is state of sadness or melancholia that has advanced to the point of being disruptive to an individuals social functioning and/or activities of daily living (ADLs). ... In medicine, inflammatory bowel disease (IBD) is a group of inflammatory conditions of the large intestine and, in some cases, the small intestine. ... This article is about the disease that features high blood sugar. ... Tuberculosis (commonly shortened to TB) is an infection caused by the bacterium Mycobacterium tuberculosis, which most commonly affects the lungs (pulmonary TB) but can also affect the central nervous system (meningitis), lymphatic system, circulatory system (Miliary tuberculosis), genitourinary system, bones and joints. ... This article discusses the medical condition. ... Prolactin is a hormone synthesised and secreted by lactotrope cells in the adenohypophysis (anterior pituitary gland). ... Testosterone is a steroid hormone from the androgen group. ... Polycystic Ovary by Sonography Polycystic ovary syndrome (PCOS, also known clinically as Stein-Leventhal syndrome), is an endocrine disorder that affects 5–10% of women. ... Hyperthyroidism (or overactive thyroid gland) is the clinical syndrome caused by an excess of circulating free thyroxine (T4) or free triiodothyronine (T3), or both. ... Hypothyroidism is the disease state caused by insufficient production of thyroid hormone by the thyroid gland. ... In medicine, adrenal insufficiency is the inability of the adrenal gland to produce adequate amounts of cortisol in response to stress. ... Located at the base of the skull, the pituitary gland is protected by a bony structure called the sella turcica. ... Human female internal reproductive anatomy Ovaries are egg-producing reproductive organs found in female organisms. ...

For most women, alteration of menstrual periods and amenorrhea is based on anovulation, or ovulating irregularly. Ovulatory menstrual periods tend to be regular and predictable in terms of cycle length, duration and heaviness of bleeding, and other symptoms. Ovulatory periods are often accompanied by midcycle symptoms such as mittelschmerz or premenstrual symptoms. In contrast, anovulation usually manifests itself as irregularity of menstrual periods, that is, unpredictable variability of intervals, duration, or bleeding. Anovulation can also cause cessation of periods (secondary amenorrhea) or excessive bleeding (dysfunctional uterine bleeding). Mittelschmerz and premenstrual symptoms tend to be absent or reduced when a woman is anovulatory. Menstrual cycle The menstrual cycle is the set of recurring physiological changes in a females body that are under the control of the reproductive hormone system and necessary for reproduction. ... Amenorrhoea (BE) or amenorrhea (AmE) is the absence of a menstrual period in a woman of reproductive age. ... Mittelschmerz (German: middle pain) is a medical term for ovulation pain. Some women have mittelschmerz regularly and can time their ovulation by it, but many never experience it. ... Dysfunctional Uterine Bleeding (DUB) is the most common cause of functional abnormal uterine bleeding, which is abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable organic pathology. ...

Chronic anovulation is a common cause of infertility. Infertility is the inability to naturally conceive a child or the inability to carry a pregnancy to term. ...

In addition to the alteration of menstrual periods and infertility, chronic anovulation can cause or exacerbate other long term problems, such as hyperandrogenism or osteopenia. It plays a central role in the multiple imbalances and dysfunctions of polycystic ovary syndrome. Androgen is the generic term for any natural or synthetic compound, usually a steroid hormone, that stimulates or controls the development and maintenance of masculine characteristics in vertebrates by binding to androgen receptors. ... Osteoporosis is a disease of bone in which bone mineral density (BMD) is reduced and bone microarchitecture is disrupted. ... Polycystic Ovary by Sonography Polycystic ovary syndrome (PCOS, also known clinically as Stein-Leventhal syndrome), is an endocrine disorder that affects 5–10% of women. ...