Normal menstruation requires integration of the hypothalamus, pituitary and ovaries, with the uterus as target organ for ovarian steroid effect. Any component in the system can go wrong and result in amenorrhoea.
- Pregnancy is the most common cause of amenorrhoea. It should be excluded, even if the woman reports being sexually inactive.
- It is useful to separate causes into: anatomical abnormality, ovarian failure, anovulation with or without oestrogen present, and androgen excess.
- The choice of appropriate investigations and their correct interpretation depend heavily on information gathered from a thorough history and physical examination.
- Genital assessment is necessary to check for anatomical obstruction in primary amenorrhoea; however, in younger patients, the progesterone withdrawal test may be a preferable way to rule out anatomical obstruction.