The primary reason for loss of the genitals, which includes the clitoris and also the labia minora and majora too, is the loss of estrogen. Levels of this hormone decline with menopause, whether it occurs naturally or because of surgery or other medical treatment. It’s estimated through clinical scanning and imaging that women lose up 80 percent of the volume of the genitals in menopause over time.
Stimulation helps somewhat to maintain the blood supply that’s a contributing factor so the “use it or lose it” phenomenon comes into play here as well as in vaginal comfort. But the primary factor is hormonal. Localized estrogen can also be helpful to maintaining the health of genital tissues.
This is another aspect of menopause that doesn’t get a lot of attention, so it’s not surprising that you’ve been surprised!