Table 1.

Terms used to describe menstrual irregularities [27].

Term	Definition
Irregular menstruation, known reason	Absent or irregular menstruation owing to use of hormonal contraception, pregnancy, breastfeeding, medical procedure, etc.
Irregular menstruation, unknown reason	Absent or irregular menstruation without a plausible explanation or reason.
Amenorrhea	Absence of menstruation for ≥3 mo.
Oligomenorrhea	Infrequent menstruation, reduced duration of flow, light or scanty flow.
Dysmenorrhea	Experience of abdominal pain, cramping, or backache during menstruation.
Menorrhagia	Frequent menstruation, increased duration of flow, and/or heavy flow.