The maintenance of female secondary sexual characteristics, as well as many other physical characteristics, such as pregnancy, baby, menstruation, etc., are regulated by the body’s hormone levels. The most obvious effect is estrogen. If a woman’s estrogen decreases, or ovarian function appears to decline, it will lead to a decrease in menstrual flow, because the endometrium loses the support of hormones, and the decrease in hormones will lead to a woman’s libido decreases, the vagina is drier, and there is no interest in sex. So if a woman has these symptoms, or hot flashes and night sweats, or increased body hair, the first thing to do is to have ovarian function, sex hormone measurements, to see if the levels of the ovaries and estrogen are normal, and if there is a real problem, you need to use hormone replacement therapy.