some info, hope it helps.
Causes of amenorrhea:
Generalized pubertal delay
Constitutional delay
Hypergonadotropic hypogonadism
Turner syndrome
Gonadal dysgenesis with mosaic karyotype
Pure gonadal dysgenesis (Perrault syndrome, Swyer syndrome)
Gonadotropin-resistant ovary syndrome
Acquired causes, eg, high-dose alkylating chemotherapy, pelvic radiation, and autoimmune oophoritis
Hypogonadotropic hypogonadism
Chronic conditions, eg, starvation, excessive exercise, depression, psychological stress, marijuana use, Crohn disease, cystic fibrosis, sickle cell disease, thalassemia major, HIV infection, renal disease, thyroid disease, diabetes mellitus, and anorexia nervosa
Slow-growing central nervous system (CNS) tumors, eg, adenomas, craniopharyngiomas, meningiomas, and pituitary microadenomas
Abnormal hypothalamic development, eg, Kallman syndrome, Prader-Willi syndrome, and Laurence-Moon-Biedl syndrome
Acquired miscellaneous disorders, eg, infiltration disorders (sarcoidosis, Langerhans cell histiocytosis, syphilis, tuberculomas), ischemia disorders (caused by trauma, aneurysm, obstruction of the aqueduct of Sylvius), and destruction (concentrated high-dose radiation exposure)
Normal puberty
Associated with hyperandrogenicity, eg, polycystic ovary syndrome, late-onset 21-hydroxylase deficiency (nonclassic congenital adrenal hyperplasia), immaturity of the hypothalamic-pituitary-ovarian axis, Cushing disease, androgen-producing ovarian or adrenal tumors, and ovarian stromal hypertrophy
Associated with absence of hirsutism or virilization, eg, immaturity of the hypothalamic-pituitary-ovarian axis and pregnancy
Hypergonadotropic hypogonadism, eg, ovarian failure, high-dose alkylating chemotherapy, pelvic radiation, and autoimmune oophoritis
Anomalies of the genital tract
Mullerian agenesis, eg, Mayer-Rokitansky-Kuster-Hauser syndrome
Congenital or acquired anatomic obstruction, eg, imperforate hymen, transverse vaginal septum, Asherman syndrome, and endometrial destruction due to severe infection