1) Amenia 2) Amenorrhea 3) Symptom 1) Amenia 2) Amenorrhea 
Amenorrhoea (BE), amenorrhea (AmE), or amenorrhœa, is the absence of a menstrual period in a woman of reproductive age. Physiological states of amenorrhoea are seen during pregnancy and lactation (breastfeeding), the latter also forming the basis of a form of contraception known as the lactational amenorrhoea method. Outside of the reproductive y...
• (n.) Retention or suppression of the menstrual discharge.
The absence of menstruation
Absence of periods i.e. no menstrual bleeding.
<gynaecology> The absence or discontinuation or abnormal stoppage of the menstrual periods. ... Synonym: amenia. ... Origin: Gr. Men = month, rhoia = flow ... (14 May 1997) ... 
Absence of menstruation. Usually applied to the reproductive years, so the usual cause is pregnancy
Absence of periods
Amenorrhoea is a medical condition being the absence or suspension of menstruation.
absence of menstrual periods, occurring either after or before menstruation has begun