The context in the menstrual cycle hormonal
The stages of the menopause transition have been classified according to the reported bleeding patterns of women, with the support of the changes in the levels of pituitary follicle-stimulating hormone (FSH).
In younger women during a normal menstrual cycle the ovaries produce estradiol, testosterone and progesterone in a cyclical pattern under the control of FSH and luteinizing hormone (LH), which both are produced by the pituitary gland. Blood estradiol levels remain relatively unchanged, or may increase approaching menopause, but usually well preserved until late menopause. This is supposed to be in response to elevated levels of FSH. However, the transition of menopause is characterized by marked variation, and often dramatic levels of FSH and estradiol, and because of this, the measurements of these hormones are not considered to be reliable guides for menopausal status exact of a woman.
Menopause is based on natural or surgical removal of estradiol and progesterone production by the ovaries, which are a part of the body's endocrine system hormone production, in this case the hormones that allow reproduction and influence sexual behavior. After menopause, estrogen still occurs in other tissues, including ovarian, but also in bone, blood vessels and even brain. However, the dramatic fall in circulating levels of estradiol in menopause affects many tissues of the brain to the skin.
In contrast to the sudden fall in estradiol during menopause, the levels of total and free testosterone and dehydroepiandrosterone sulfate (DHEAS) and androstenedione appear to decline more or less steadily with age. Not observed an effect of natural menopause on circulating androgen levels. Therefore tissue-specific effects of natural menopause cannot be attributed to the loss of androgen hormone production. However, women who have had their ovaries removed surgically, who have had their ovaries damaged by chemotherapy or radiotherapy, or who have ovarian gonadotropin suppression, have loss of ovarian androgen production as a result.
Menopause can be induced surgically by bilateral oophorectomy (removal of the ovaries), which is often, but not always, made in conjunction with the extraction of the fallopian tubes (salpingo-oophorectomy), and the uterus (hysterectomy). The cessation of menses as a result of the removal of the ovaries is called "surgical menopause." The sudden and complete drop in hormone levels usually produces extreme withdrawal symptoms such as hot flashes, etc. Removal of the uterus without removing the ovaries, a hysterectomy does not cause menopause, although pelvic surgery can often trigger a little earlier menopause, perhaps because of a compromised blood supply to the ovaries.