Cycle abnormalities
from wikipedia.org
Anovulation
Apparently normal menstrual flow can occur without ovulation preceding it (anovulatory cycle - "an-" meaning "absence of" +ovulation). In some women, follicular development may start but not be completed; nevertheless, estrogens will form and will stimulate the uterine lining. Anovulatory flow resulting from a very thick endometrium caused by prolonged, continued high estrogen levels is called estrogen breakthrough bleeding. Anovulatory bleeding triggered by a sudden drop in estrogen levels is called estrogen withdrawal bleeding.
Anovulatory bleeding may occur on a regular basis, but more commonly happens with irregular frequency. Anovulatory flow commonly occurs prior to menopause (premenopause) or in women with polycystic ovary syndrome.
Infrequent or irregular ovulation is called oligoovulation.
Flow
Sudden heavy flows or amounts in excess of 80 ml (hypermenorrhea or menorrhagia) are not normal.
Very little flow (less than 10ml) is called hypomenorrhea.
Prolonged flow (metrorrhagia, also meno-metrorrhagia) no longer shows a clear interval pattern. Dysfunctional uterine bleeding refers to hormonally caused flow abnormalities, typically anovulation.
All bleeding abnormalities need medical attention; they may indicate hormone imbalances, uterine fibroids, or other problems. As pregnant patients may bleed, a pregnancy test forms part of the evaluation of abnormal flow.
Cycle length
The medical term for cycles with intervals of 21 days or fewer is polymenorrhea and, on the other hand, the term for cycles with intervals exceeding 35 days is oligomenorrhea (or amenorrhea if intervals exceed 180 days).
Amenorrhea refers to a prolonged absence of menses during the reproductive years of a woman. For example, women with very low body fat, such as athletes, may cease to menstruate. Amenorrhea also occurs during pregancy.
Early menarche
The condition precocious puberty has caused menstruation to occur in girls as young as eight months old.
