What is vaginal discharge?
Vaginal discharge is the name we give to the secretion of fluids from the vagina, which, depending on its characteristics, can be something completely normal or a sign of gynecological disease.
Natural vaginal secretions are produced by glands in the vaginal canal and play an important role in women’s health as they help to remove dead cells and bacteria from the reproductive system. This keeps the vagina clean and helps prevent infections.
In general, clear discharges, which are not associated with other symptoms, are benign and do not need treatment. On the other hand, if the discharge is greenish or yellowish in color, smells bad, and is associated with pain or itching, it is likely a sign of a gynecological infection.
In this article we will cover the main causes of vaginal discharge, detailing the signs and symptoms that may indicate vaginitis or colpitis (inflammation of the vagina).
normal vaginal discharge
Before we talk about physiological vaginal discharge, that is, normal vaginal discharge, not related to disease, we have to do a quick review of the female gynecological anatomy.
Confusion between vagina and vulva is very common. When we look at the female external genitalia what we see is the vulva; of the vagina we can only see its external orifice, as the vagina itself is a channel that is inside the body and ends at the cervix, as seen in the illustration below.
The discharge normally originates in the vagina and only becomes noticeable when it comes out of the vagina’s external orifice. In some cases, the discharge may originate from the cervix.
All women of childbearing age can have a normal vaginal discharge, called a physiological vaginal discharge. This discharge is formed by the combination of dead vagina cells, natural bacteria from the vaginal flora and mucus secretion; it usually has between 1 and 4 ml of daily volume and its function is to moisten, lubricate and keep the vagina clean, making it difficult for infections to appear.
Physiological vaginal discharge is stimulated by estrogen and, therefore, it may have its volume increased in periods when there is greater hormonal stimulation, such as in pregnancy, use of estrogen-based contraceptives, in the middle of the menstrual cycle , close to ovulation or days before of menstruation.
A normal vaginal discharge usually has the following characteristics: it may be thick, watery, or elastic; its color is white, milky or transparent; and it has very mild odor or no odor at all.
One of the most important tips to identify a physiological discharge is the absence of signs or symptoms of irritation, such as pain, burning, redness or itching in the vagina and/or vulva. However, it is important to point out that a slight irritation of the vulva can occur in some women with a physiological discharge.
abnormal vaginal discharge
Leukorrhea or pathological vaginal discharge is one that is related to some gynecological disease. This type of discharge can have several causes. The most common are vaginitis, also called colpititis, which is an infection of the vagina, usually caused by bacteria or fungi. Discharge can also arise from atrophy of the lining of the vagina after menopause, allergy to some substances – such as spermicides – or the presence of a foreign body in the vagina.
Let’s talk briefly about the main causes of vaginitis and vaginal discharge. More details can be read in the specific texts for each of the diseases described below.
Candida is a fungus that is part of the natural germ flora of the vagina, skin and intestines. Candida normally lives on our skin and does not usually cause symptoms. However, whenever there is any disorder in our body’s usual conditions, such as excessive use of antibiotics, stress, diseases such as diabetes, immunosuppression, trauma, etc., Candida can start to multiply excessively, starting to cause symptoms.
Vaginal candidiasis usually presents with itching (itching) and/or burning in the vulva, pain when urinating, pain during intercourse, and a thick discharge without a strong, whitish odor, often compared to cottage cheese.
Gonorrhea and Chlamydia
Gonorrhea and Chlamydia are two sexually transmitted diseases (STDs) caused respectively by the bacteria Neisseria gonorrhoeae and Chlamydia trachomatis . Both diseases cause cervicitis (infection of the cervix) and may present with vaginal discharge, usually with a mucopurulent appearance (cloudy yellow). Other associated symptoms include pain when urinating, pain during intercourse, usually with post-coital bleeding, and vulval irritation.
Trichomoniasis is a sexually transmitted disease caused by a protozoan called Trichomonas vaginalis. Trichomoniasis vaginitis usually presents with a thin, greenish-yellow, unpleasant-smelling discharge associated with the other classic signs of vulvovaginitis such as painful urination, vulval irritation, and bleeding/pain during intercourse.
The Trichomonas vaginalis can remain asymptomatic for a long time, making it difficult to know exactly when there was contamination.
Bacterial vaginosis is the main cause of abnormal vaginal discharge. It is an infection caused by changes in the natural flora of the vagina, which result in a reduction in the number of lactobacillus (“good” bacteria) and an excessive growth of aerobic bacteria (“bad” bacteria) such as Gardnerella vaginalis, Mycoplasma hominis, Prevotella, Porphyromonas , Bacteroides, Peptostreptococcus, Fusobacterium and Atopobium vaginae .
It is very common to associate bacterial vaginosis with the bacterium Gardnerella vaginalis , however, this disease is caused by the growth of multiple bacteria, not just Gardnerella . The term vaginosis is used instead of vaginitis in this case because there is little or no inflammation of the vagina, just bacterial proliferation.
The typical symptom of vaginosis is a thin, grayish vaginal discharge with a very strong odor, like rotten fish. The other symptoms of vulvovaginal inflammation, such as pain when urinating, itching of the vulva and pain during intercourse, are much less frequent, being in most cases absent.
The proliferation of bacteria and the drop in the number of lactobacillus causes a significant increase in the pH of the vagina, which is one of the tips for diagnosis.
Atrophy of the vagina usually occurs after menopause . Estrogen stimulates physiological discharge, and its absence causes dryness and thinning of the vaginal mucosa. This vaginal atrophy can lead to inflammation with discharge, pain to urinate and discomfort during sexual intercourse .
Allergy to condom lubricant , spermicides, perfumes, soaps or personal care products, etc., can cause an allergic reaction in the vagina/vulva, leading to the appearance of a discharge.
Less common causes
The causes mentioned above are the most common, but they are not the only ones. If the woman has a persistent vaginal discharge, which does not appear to be physiological, and none of the common causes are identified, the gynecologist must also consider the following hypotheses:
- HPV infection .
- Genital herpes .
- Cancer of the cervix.
- Semen allergy (rare cause).
- Vulvovaginitis caused by Streptococcus bacteria .
- Foreign body retained inside the vagina (internal absorbent or “lost” condom, for example).
- Pinworm worm infection .
- Pelvic inflammatory disease .
Vaginal discharge according to its characteristics
Any situation that causes some degree of vaginal or uterine bleeding can cause a brownish discharge. The main causes are:
- Remnants of menstruation mixed with physiological discharge.
- Trauma in the vaginal or uterine region.
- Foreign body in the vagina.
- Gynecological tumors.
- Uterine bleeding caused by the implantation of the embryo in the uterus in the first days of pregnancy.
- Vaginal atrophy.
- Ectopic pregnancy.
A yellowish vaginal discharge is usually a sign of a gynecological infection, especially if accompanied by a bad smell, burning or itchy vagina. The main causes are:
The physiological discharge is usually white and clear, but when exposed to air after contact with the panties, it can turn a little yellow. Therefore, if the woman has no symptoms and the discharge does not smell, the fact that it is slightly yellow does not necessarily indicate an ongoing infection. When in doubt, it is best to go to your gynecologist so that she can assess the discharge.
white or graying
A white discharge is usually normal, especially if it is thin, small in quantity, and occurs near the ovulatory period. However, if the discharge is thick, pasty, milky, lumpy or grayish, especially if it is associated with irritating symptoms such as itching, vaginal pain or foul odor, infections should be investigated. The main causes are:
- Bacterial vaginosis.
A foul-smelling discharge is typical of a gynecological infection. The main causes are:
- Bacterial vaginosis (very strong smell).
To correctly distinguish the types of vaginal discharge, it is necessary to consult a gynecologist. Through the gynecological exam it is possible to notice if there is vaginitis, cervicitis or just a discharge without signs of inflammation. It is also possible to take samples of the discharge for evaluation of the vaginal pH, microscopic investigation and culture.
Treatment for a discharge depends on the cause, ranging from antifungals or antibiotics for infections, to estrogen creams for atrophic vaginitis. There is no single treatment that fits all types of discharge.
If you have vaginal discharge, see your gynecologist so that the cause is clarified and the appropriate treatment can be instituted.
- Frequently asked questions. Women’s health: Vulvovaginal health – American College of Obstetricians and Gynecologists.
- Vaginal discharge – Mayo Clinic.
- Vaginal Discharge – Palo Alto Medical Foundation (PAMF).
- Evaluation of vaginal complaints – JAMA.
- Approach to women with symptoms of vaginitis – UpToDate.