Amenorrhea

Amenorrhea-Absence/ cessation of menstruation in excess of 6 months

Primary: Normal sexual development: No onset of menstruation by age of 16
              Abnormal sexual development: No onset of menstruation by the age of 14

Etiology:
Mayer-Rokitansky-Kuster-Hauser (Mullerian Agenesis)-Outflow tract/ and uterus disorder
Kallmann Syndrome (Hypogonadotrophic hypogonadism & anosmia-loss of smell sensation)-Hypothalamo-Pituitary Axis disorder
Turner's Syndrome (XO-chromosomal abnormalities)-Ovary disorder

Secondary: In previously menstruating women: Absence of menstruation in excess of 6 months (if cycle regular), 12 months (if known to have oligomenorrhea-reduction in frequency of menstruation (6 weeks-6 months)

Etiology:
Stein-Leventhal Syndrome-Polycystic Ovary Syndrome (PCOS)
Asherman's Syndrome- Intrauterine adhesions