Although some female friends have basic menstrual patterns, there is always a small amount of spotting or bloody discharge a few days before each official menstruation, and then they usher in formal menstruation (larger amount, brighter color, shedding endometrium, accompanied by typical menstrual symptoms such as lower abdominal distension and backache).
Bleeding outside of menstruation is always a concern, so how does this happen? Is there any harm? Do I need to see a doctor? See if this article can help you clear the doubts in your mind.
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The basics of menstruation
To understand the causes of premenstrual bleeding, you need to understand the fundamentals of menstruation.
The lining of our uterus is covered with the endometrium, and just as the skin is divided into dermis and epidermis, the endometrium is divided into two layers. The superficial layer is the functional layer, which is the part that falls off with each menstrual period. The inner layer is the basal layer and is responsible for the production of new functional layers.
Image from Reference [1]
After a menstrual period, the old functional layer of the endometrium is shed, and the new functional layer slowly grows with the support of estrogen. After the follicle releases the egg, the remaining part becomes the corpus luteum, producing estrogen and progesterone to support further thickening and development of the endometrium in preparation for embryo implantation.
If there is early embryo implantation, blood vessels and glands in the functional layer can support further embryonic development; What happens if I have a brown discharge before my period? Doctor answers...
With conception, the corpus luteum will lose its function 14 days after ovulation, estrogen and progesterone will decline rapidly, and the endometrium will also shrink and fall off due to the loss of the support of estrogen and progesterone of the corpus luteum, accompanied by the rupture of small blood vessels, bleeding, and exudation, which will be excreted from the body as menstruation.
Therefore, menstruation is essentially the product of endometrial renewal, and hormones and endometrium play a key role in the formation of menstruation.
Knowing this, it is easier to understand why there is premenstrual bleeding: hormonal fluctuations and endometrial abnormalities can be the cause of premenstrual bleeding.
Premenstrual bleeding
Possible causes
1
Premenstrual bleeding due to hormonal fluctuations
Estrogen and progesterone support the growth and development of the endometrium, and if there are significant hormonal fluctuations before menstruation that affect the stability of the endometrium, it can cause a small amount of bleeding in the endometrium.
Endogenous hormonal fluctuations can be caused by luteal insufficiency, interference of high prolactin during lactation, immature ovarian function during puberty, decline of perimenopausal ovarian function, polycystic ovary syndrome and other factors, stress, sleep, weight changes, dietary changes, environmental changes, etc., which can also affect hormone secretion and cause premenstrual bleeding.
Exogenous hormonal fluctuations, such as oral hormone-containing drugs (e.g., emergency contraceptives, short-acting contraceptives), use and discontinuation of medicated intrauterine devices, can also affect the hormonal balance in the body and cause premenstrual bleeding.
2
Premenstrual bleeding due to endometrial abnormalities
A healthy endometrium can tolerate a range of hormonal fluctuations, and mild hormonal fluctuations can also cause endometrial bleeding if there are lesions in the endometrium or if it is affected by some disease.
Some infectious diseases, such as inflammation of the endometrium, can manifest as spotting before menstruation. Sometimes, diseases such as endometrial polyps, uterine fibroids, and endometriosis can also affect the stability of the endometrium, and symptoms of premenstrual bleeding appear.
Some systemic diseases, such as thyroid dysfunction, coagulation dysfunction, platelet dysfunction, etc., can also cause premenstrual bleeding.
3
"Premenstrual bleeding" due to pregnancy
Sometimes, pregnancy can also cause symptoms similar to bleeding before menstruation.
About 10 days after normal conception is the time for early embryo implantation, and implantation bleeding sometimes occurs at this stage, which is generally less and can stop on its own, and there is no obvious discomfort, which makes many people mistakenly believe that there is premenstrual bleeding or a small menstrual period, thus delaying the diagnosis of pregnancy. However, implantation bleeding does not harm the health of the woman nor affects the development of the embryo, and the harm is very small, and the other condition is much more dangerous.
If the embryo does not implant normally, but an ectopic pregnancy (commonly known as an ectopic pregnancy) occurs, it can also cause a small amount of bleeding from the lining of the uterus. This bleeding can occur at the time of the expected menstrual period or before or after the expected menstrual period, so it is often mistaken for premenstrual bleeding or abnormal menstruation, delaying treatment.
Even if the embryo implants normally in the uterus, it may cause threatened miscarriage for some reasons, such as vaginal bleeding, lower abdominal pain, uterine effusion, etc., and sometimes it can be confused with premenstrual bleeding or abnormal menstruation.
4
Other reasons
Bleeding from some cervical lesions can also mimic premenstrual bleeding. Chronic cervicitis, cervical polyps, cervical cancer and other diseases can make the cervical tissue fragile and congested, so it is often manifested as vaginal bleeding after intercourse, and the bleeding symptoms can be spotting, vaginal bloody discharge, or a small amount of vaginal bleeding and increased menstrual flow. If it happens to occur before menstruation, it can also be mistaken for premenstrual bleeding.
When to see a doctor
The causes of premenstrual bleeding are complex, and there are special conditions that need to be identified, so the need for medical attention depends on the specific situation.
If premenstrual bleeding occurs incidentally, it is a priority to determine whether pregnancy is possible. If pregnancy is possible, it is necessary to see a doctor to confirm the pregnancy to rule out ectopic pregnancy, etc.; If it is not possible to get pregnant, you can observe it for the time being. Bleeding caused by occasional hormone fluctuations, medications, etc., often improves on its own when the stimulus is removed.
If there is frequent premenstrual bleeding, bleeding in other phases of menstruation, heavy bleeding, foul smell of bleeding, or premenstrual bleeding accompanied by vulvovaginal discomfort, lower abdominal pain, unexplained fever, unexplained weight loss, fatigue, etc., medical attention is required.
If you are trying to conceive, or if your pregnancy is confirmed, you will also need to tell your doctor about vaginal bleeding.
I wonder if this article can answer the doubts in your mind? If you have any menstrual problems, you can also leave a message in the comment area~
bibliography
[1] Xie Xing, Kong Beihua, Duan Tao, eds.; Lin Zhongqiu, Di Wen, Martin, Cao Yunxia, Qi Hongbo, deputy editors. Beijing: People's Medical Publishing House, 2018
Planning and production
Author丨Flying knife and rain doctor
Audit丨Lan Yibing, Deputy Chief Physician, Obstetrics and Gynecology Hospital, Zhejiang University School of Medicine