During normal menstruation approximately 40 mL of blood and an additional 35 mL of serous fluid are lost. The menstrual fluid is normally non-clotting because a fibrinolysin is released alongwith necrotic endometrial material. The cause of menopause is burning out of the ovaries. At about age 45 years only a few primordial follicles remain to be stimulated by FSH and LH. The estrogen production fall below a critical value and the gonadotropic hormones (FSH and LH ) are produced regularly from the pituitary so, there level increase in body.