These range from problems with the uterus
and or outflow tract, to problems with the brain regulation of the ovaries or problems with the ovaries themselves, to amenorrhea due to too little body fat or too excessive stress
. Some girls will simply have delayed puberty
without any identifiable cause as well. Girls who have not started sexual development by the age of 14 or have not had menstrual
cycles by the age of 16 merit evaluation by an endocrinologist.