N91 - Absent, scanty and rare menstruation
Excludes 1:
-ovarian dysfunction (E28.-)
N91.0 - Primary amenorrhea
N91.1 - Secondary amenorrhea
N91.2 - Amenorrhea, unspecified
N91.3 - Primary oligomenorrhea
N91.4 - Secondary oligomenorrhea
N91.5 - Oligomenorrhea, unspecified