There are many reasons for low menstrual flow in 23-year-old women, as follows: 1, poor ovarian function: poor, low or even failing ovarian function may manifest as low menstrual flow or scanty menstruation, which can generally be determined by blood tests for endocrine six and ovarian AMH. 2, multiple abortions or curettage: may damage the basal layer of the endometrium and even produce scarring and cavity adhesions. 3, polycystic ovary syndrome, hyperprolactinemia, abnormal thyroid function: may affect female ovulation, resulting in reduced menstrual volume. 4, frequent strenuous exercise, weight loss, dieting: may affect female endocrine secretion, resulting in reduced menstrual volume, even thinning, amenorrhea.