Estradiol is required for the structure and function of genital tissues, especially the vagina. Estradiol hormone helps keep the vaginal tissue healthy by maintaining normal vaginal lubrication, tissue elasticity and acidity (pH should be approximately 4.0). Estradiol helps create a natural defense against vaginal and urinary tract infections.
The ovaries and adrenal glands produce estradiol. As a woman ages, there is a decline in the amount of estradiol secreted. Decreased estradiol levels are associated with a thinner, less elastic and more fragile vaginal epithelial lining. The decline in estradiol levels with aging also causes menstruation to become infrequent and ultimately to discontinue altogether. The body attempts to get the ovaries to produce more estrogen by increasing follicle-stimulating and luteinizing hormone (FSH and LH).
Blood tests to determine estradiol values are obtained most commonly to evaluate ovarian function. A common reason for blood test measurement of estradiol is to monitor menopausal hormone therapy with bioidentical estradiol hormone. Decreased estradiol levels are the main cause of vaginal dryness in menopause. Other uses for estradiol blood tests include diagnosis of the cause of precocious puberty in young girls. Another use is in the differential diagnosis of lack of menstrual periods. Estradiol values can be used to distinguish whether the cause of amenorrhea is menopause, pregnancy, or a medical problem. Serial measurements of estradiol are used to monitor follicle development in the ovary. Decreased levels of estradiol are seen in hypopituitarism, hypogonadism, peri-menopause, menopause and post-menopause, childbirth, breast feeding, polycystic ovary syndrome, cancer therapies such as radiation therapy, hormone ablation therapy and chemotherapy, anorexia nervosa, extreme endurance exercise, and surgical removal of the ovaries.
Women with low estradiol values may have other symptoms than vaginal dryness. Hot flashes from low estradiol are sudden periods of sweating, flushing, and feeling overheated that can be followed by a period of being cold and having shivers. When hot flashes occur at night, they can interfere with sleep, and then cause fatigue, cognitive impairment, and mood disturbances. Many women with low estradiol complain of decreased memory and slowed thought processes during menopause. Depression and mood disturbances from low estradiol are also common during menopause. Osteoporosis from low estradiol can result in brittle bones that are susceptible to fracture. Heart disease risk associated with low estradiol also rises after menopause.