Estrogen deficiency has both vaginal and urologic effects; the female genitalia and lower urinary tract share common estrogen receptor function due to their embryological development. Estrogen is a vasoactive hormone (one that affects blood pressure) which stimulates blood flow and increases vaginal secretions and lubrication. Activated estrogen receptors also stimulate tissue proliferation in the vaginal walls, which contribute to the formation of rugae. This rugae aids in sexual stimulation by becoming lubricated, distended, and expanded. Genitourinary effects of low estrogen include thinning of the vaginal epithelium, loss of vaginal barrier function, decrease of vaginal folding, decrease of the elasticity of the tissues, and decrease of the secretory activity of the Bartholin glands, which leads to traumatization of the vaginal mucosa and painful sensations. This thinning of the vaginal epithelium layers can increase the risk of developing inflammation and infection, such as urinary tract infection. The vagina is largely dominated by bacteria from the genus Lactobacillus, which typically comprise more than 70% of the vaginal bacteria in women. These lactobacilli process glycogen and its breakdown products, which result in a maintained low vaginal pH. Estrogen levels are closely linked to lactobacilli abundance and vaginal pH, as higher levels of estrogen promote thickening of the vaginal epithelium and intracellular production of glycogen. This large presence of lactobacilli and subsequent low pH levels are hypothesized to benefit women by protecting against sexually transmitted pathogens and opportunistic infections, and therefore reducing disease risk.
Hypoestrogenism
Hyperestrogenism
Antiestrogen withdrawal response
Corticosteroid-induced lipodystrophy
Hyperandrogenism
Androgen deficiency
Thyroid hormone resistance
Progestin-induced virilization