What causes vaginal bleeding in postmenopausal women?

Menopause in women refers to the decline of ovarian function and the cessation of menstruation. Natural menopause refers to the exhaustion of ovarian follicles, or the loss of response of the remaining follicles to gonadotropins. The follicles no longer develop and secrete estrogen, and cannot stimulate the growth of the endometrium, leading to menopause. Menopause represents the decline of ovarian function, depletion of estrogen secretion, cessation of menstruation, and termination of reproductive function. Menopause is calculated based on the time of the last menstrual period for women over 40 years old. Most women go through menopause between the ages of 45 and 55. So what causes vaginal bleeding in women after menopause?

Perimenopause refers to the period before and after menopause in women, when ovarian function begins to decline and lasts until one year after the last menstrual period. This period is mainly characterized by anovulatory dysfunctional uterine bleeding. Perimenopausal functional uterine bleeding is mostly caused by ovarian failure, anovulation, and sex hormone disorders. Not every premenopausal woman experiences functional uterine bleeding. Perimenopausal functional uterine bleeding is also related to local factors of the endometrium.

Causes

1. Abnormal vascular morphology

Abnormal vascular morphology includes perivascular fibrosis, subintimal hyalinization, vascular smooth muscle hyperplasia or hypertrophy, and vascular elastic tissue degeneration. Abnormal spiral arterioles interfere with the endometrial microcirculation function, affect the shedding of the endometrial functional layer and the repair of blood vessels and epithelium on the detachment surface, affect vasomotion and local coagulation and fibrinolysis functions, and lead to abnormal uterine bleeding.

2. Enhanced fibrinolytic activity

During functional uterine bleeding, the amount of endometrial plasmin-activating substances increases and their activity is enhanced, activating plasminogen to form plasmin. Plasmin cleaves fibrin, increasing fibrin degradation products (FDP) and reducing plasma fibrin, resulting in a defibrinogenated state in the uterus, which affects the coagulation and hemostasis process at the top of the normal endometrial spiral arterioles and the vascular lake, leading to long-term massive bleeding.

3. Abnormal local prostaglandin production

Large amounts of estrogen without progestin opposition can lead to increased secretion of prostacyclin (PGI2) by cultured endometrial capillary endothelium. As a result, the balance between PGI2 and thromboxane A2 (TXA2), which mainly regulate local blood volume, spiral arterioles, muscle contraction activity and coagulation factors in the uterus, is disturbed. Under the action of a large amount of PGI2, the uterine spiral arterioles and microvessels dilate, thrombosis is blocked, and uterine bleeding time is prolonged.

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4. Abnormal number and function of lysosomes

The lysosomal function of endometrial cells is regulated by sex hormones, which directly affects the synthesis of prostaglandins and is thus related to endometrial shedding and bleeding. When progesterone levels decrease before menstruation or the ratio of estrogen to progesterone is unbalanced during functional uterine bleeding, the stability of the lysosomal membrane will be destroyed, causing phospholipase A2 to precipitate and be released from the lysosomes and enter the cytoplasmic cells, causing arachidonic acid activation and the formation of large amounts of prostaglandins (PGs). On the other hand, lysosomal membrane rupture allows the precipitation and release of destructive hydrolases, which will cause intimal cell rupture, collapse of the intimal layer, necrosis and hemorrhage.

What causes vaginal bleeding in postmenopausal women? Because anovulatory dysfunctional uterine bleeding first has amenorrhea for several weeks or months, followed by heavy bleeding, it may also start with irregular vaginal bleeding. If you experience irregular menstrual cycles, amenorrhea or frequent menstruation during menopause, irregular bleeding volume and varying lengths of menstrual periods, you should go to the hospital for examination. In severe cases, surgical treatment can be considered.