What is the cause of brown discharge before menstruation? Doctors answer...

Although some female friends have basically regular menstruation, they always have a small amount of spotting or bloody discharge a few days before the official menstruation, and then the official menstruation comes (larger volume, brighter color, with shed endometrium, accompanied by typical menstrual symptoms such as lower abdominal distension and back pain).

Bleeding outside of your period is always a cause for concern. So how does this happen? Is there any harm? Do you need to see a doctor? See if this article can help you resolve your concerns.

The basics of menstruation

To understand the cause of premenstrual bleeding, you need to first understand the basic principles of menstruation. The inner wall of our uterus is covered with the endometrium, which is divided into two layers, just like the dermis and epidermis of the skin. The outer layer is the functional layer, which is shed every time you menstruate. The inner layer is the basal layer, which is responsible for producing new functional layers.

Image from reference [1]

After a menstrual period, the old functional layer of the endometrium falls off, and the new functional layer slowly grows with the support of estrogen. After the follicle discharges the egg, the remaining part becomes the corpus luteum, which produces estrogen and progesterone to support the further thickening and development of the endometrium, so that it is ready for embryo implantation. If there is early embryo implantation, the blood vessels and glands of the functional layer can support the further development of the embryo; if there is no conception, the corpus luteum will lose its function 14 days after ovulation, and estrogen and progesterone will drop rapidly. The endometrium will also atrophy and fall off due to the loss of the support of the corpus luteum and estrogen and progesterone, accompanied by the rupture, bleeding and exudation of small blood vessels, and will be discharged 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: hormone fluctuations and endometrial abnormalities can both be causes of premenstrual bleeding.

Possible causes of premenstrual bleeding

1. Premenstrual bleeding caused by hormone fluctuations

Estrogen and progesterone support the growth and development of the endometrium. If there is a significant enough hormonal fluctuation before menstruation that affects the stability of the endometrium, it can cause a small amount of endometrial bleeding. Endogenous hormone fluctuations can be caused by factors such as luteal insufficiency, interference from high prolactin during lactation, immature ovarian function during adolescence, ovarian function decline during perimenopause, polycystic ovary syndrome, etc. Stress, sleep, weight changes, changes in diet structure, and environmental changes can also cause premenstrual bleeding by affecting hormone secretion. Exogenous hormone fluctuations, such as oral medications containing hormones (such as emergency contraceptives, short-acting contraceptives), the use and discontinuation of medicated intrauterine devices, etc., can also affect the hormone balance in the body and cause premenstrual bleeding.

2Premenstrual bleeding caused by endometrial abnormalities

A healthy endometrium can withstand a certain range of hormonal fluctuations. If there are lesions in the endometrium or it is affected by some diseases, slight hormonal fluctuations can also lead to endometrial bleeding. Some infectious diseases, such as endometrial inflammation, 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 cause symptoms of premenstrual bleeding. Some systemic diseases, such as abnormal thyroid function, abnormal coagulation function, and abnormal platelet function, can also cause premenstrual bleeding.

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3. Premenstrual bleeding caused by pregnancy

Sometimes, pregnancy can also cause symptoms similar to premenstrual bleeding. Normally, about 10 days after conception is the time for early embryo implantation. Implantation bleeding sometimes occurs during this stage. The amount of bleeding is generally small and can stop on its own, and there is no obvious discomfort. This makes many people mistakenly believe that they have premenstrual bleeding or a light menstrual period, thus delaying the diagnosis of pregnancy. However, implantation bleeding will neither harm women's health nor affect the development of the embryo, and the harm is very small. The other situation is much more dangerous.

If the embryo does not implant normally, but an ectopic pregnancy occurs (commonly known as an ectopic pregnancy), it can also cause a small amount of endometrial bleeding. This bleeding can occur at the expected menstrual period, before or after the expected menstrual period, so it is often mistaken for premenstrual bleeding or abnormal menstruation, thus delaying treatment.

Even if the embryo implants normally in the uterus, symptoms of threatened abortion may occur due to some reasons, such as vaginal bleeding, lower abdominal pain, uterine fluid accumulation, etc. Sometimes, it may be confused with premenstrual bleeding or abnormal menstruation.

4Other reasons

Bleeding caused by some cervical lesions can also have similar symptoms as premenstrual bleeding. Chronic cervicitis, cervical polyps, cervical cancer and other diseases can make the cervical tissue fragile and congested, so it often manifests as vaginal bleeding after intercourse. Bleeding symptoms can be spotting, bloody vaginal discharge, or a small amount of vaginal bleeding and increased menstrual flow. If it happens before menstruation, it may also be misdiagnosed as premenstrual bleeding.

When do you need medical attention?

The causes of premenstrual bleeding are very complicated, and there are some special circumstances that need to be identified, so whether medical treatment is needed depends on the specific situation. If premenstrual bleeding occurs occasionally, it is necessary to first determine whether there is a possibility of pregnancy. If pregnancy is possible, you need to see a doctor to confirm the pregnancy to rule out ectopic pregnancy and other conditions; if pregnancy is not possible, you can observe for the time being. Bleeding caused by occasional hormone fluctuations, medication, etc. can often improve on its own after the stimulus is removed. If premenstrual bleeding occurs frequently, there is bleeding in other stages of menstruation, the amount of bleeding is large, the bleeding has an odor, or premenstrual bleeding is accompanied by vulvar and vaginal discomfort, lower abdominal pain, unexplained fever, unexplained weight loss, fatigue, etc., medical treatment is required. If you are preparing for pregnancy, or early pregnancy is confirmed, you also need to inform your doctor of vaginal bleeding. I wonder if this article can answer your doubts? If you have any other menstrual problems, you can also leave a message in the comment area~

References

[1] Xie Xing, Kong Beihua, Duan Tao (eds.); Lin Zhongqiu, Di Wen, Martin, Cao Yunxia, ​​Qi Hongbo (co-eds.). Obstetrics and Gynecology, 9th edition [M]. Beijing: People's Medical Publishing House, 2018.

Planning and production

Author: Doctor Feidao Duanyu

Reviewer: Lan Yibing, deputy chief physician, Department of Obstetrics and Gynecology, Zhejiang University School of Medicine

Planning丨Yang Yaping

Editor: Yang Yaping

Proofread by Xu Lailinlin