<unk> s can be classified as endocrine disorders or as a disorders of the reproductive system.
If the egg fails to release from the follicle in the ovary an<unk>  cyst may form. Small<unk>  cysts are common in healthy women. Some women have more follicles than usual (polycystic ovary syndrome), which inhibits the follicles to grow normally and this will cause cycle irregularities.
Other conditions include:<unk>  cancer
Hypogonadism
Ovarian disease
Pelvic tumor
Pregnancy
Epithelial ovarian tumors
Uterine cancer
Hysteria
Ovarian cyst
Fallopian tube cancer