What causes vaginal bleeding?

The most common cause of vaginal bleeding in women is menstruation, but some women also experience bleeding during non-menstrual periods. After all, the vagina is an important reproductive organ for women. Many women are afraid of suffering from serious diseases and are very concerned about the cause. So, what is vaginal bleeding? Let’s take a closer look at it.

1. When there is an imbalance in sex hormone secretion and anovulatory functional uterine bleeding, the single and long-term estrogen stimulation causes the endometrium to proliferate progressively, proliferate to a highly adenocystic type, adenomatous hyperplasia, and even gradually become endometrial cancer. Due to the lack of progesterone antagonism and glandular secretion, the endometrium is thickened, the glands increase, the glandular cavity is enlarged, and the glandular epithelium proliferates abnormally. The intimal blood supply increases and the spiral arterioles become tortuous. The polymerization and gelation of acidic particulate polysaccharide (AMPS) caused by estrogen reduces the permeability of blood vessels in the interstitium, affects the exchange of substances, causes local endometrial tissue ischemia, necrosis, and shedding, and causes bleeding. The coagulation effect of acidic particulate polysaccharide also hinders the shedding of the endometrium, causing asynchronous exfoliation of the endometrium and causing long-term irregular bleeding of the endometrium.

When there is ovulatory functional uterine bleeding, the corpus luteum may degenerate prematurely, resulting in a short luteal phase and frequent menstruation; or it may be incompletely atrophied and continuous secretion of progesterone, resulting in luteal phase (premenstrual) bleeding, prolonged menstruation, and continuous spotting, or both. The mechanism is insufficient secretion of estrogen and progesterone, especially insufficient secretion of progesterone, which causes the endometrium to be completely secreted, with immature development of glands, stroma and blood vessels, and due to the asynchronous withdrawal of estrogen and progesterone, irregular exfoliation of the endometrium and abnormal bleeding occur.

2. The role of prostaglandins It is known that prostaglandins (PGs), especially PGE2, PGF2 thromboxane (TXA2) and prostacyclin (PGL2), are a group of highly active vascular and coagulation function regulatory factors. They affect endometrial bleeding function by regulating uterine blood flow, spiral arterioles and microcirculation, muscle contraction activity, endometrial lysosomal function and coagulation fibrinolytic activity.

TXA2 is produced in platelets, which causes microvascular constriction. Platelet aggregation, thrombosis, and hemostasis. PGL2 is produced in the blood vessel wall and has the opposite effect to TXA2, strongly dilating the microvessels, resisting platelet aggregation and preventing thrombosis. PGFa can cause constriction of endometrial spiral arteries, while PGE2 can dilate blood vessels. So TXA2 and PGL2, PGF2a. Disturbances in PGE2 function and dynamic balance can cause endometrial bleeding.

3. Abnormal structure and function of endometrial spiral arterioles and lysosomes 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 vasoconstriction and local coagulation and fibrinolysis function, and lead to abnormal uterine bleeding. From the follicular phase to the luteal phase, the number of lysosomes and the activity of their enzymes increase progressively. Progesterone stabilizes while estrogen destabilizes the lysosomal membrane. Therefore, when the estrogen/progesterone ratio is unbalanced before menstruation, the stability of the lysosomal membrane will be destroyed. The rupture of the lysosomal membrane will cause the precipitation and release of destructive hydrolases, which will cause endometrial cell rupture, endometrial layer collapse, necrosis and bleeding.

The above is an introduction to what causes vaginal bleeding. I hope it will be helpful for women to understand. There are many factors that cause vaginal bleeding in women, all of which are common gynecological diseases in life. When this happens, you must go to a regular hospital for examination and diagnosis in time to avoid the disease causing more serious consequences to women's health.