Vaginitis Smelly Vaginal Discharge

Many people knock on the clinic door because of an odor that doesn't go away even after showering, a fishy smell rising from their underwear. What concerns people even before the amount or color of discharge is precisely the odor, and in fact the grain of this odor is an important clue that lets us gauge the cause. Vaginal discharge changes in amount and consistency each time according to the ovulation day and menstrual cycle, and after menopause, as female hormones decrease, viscous discharge decreases and it can rather become dry. So in the clinic, even for someone who comes complaining of discharge, we look together at several clues including odor to differentiate the cause. In this article, I will organize, putting odor at the center, which vaginitis is suspected and how to respond.

A certain degree of vaginal odor is in the normal range that everyone has. The American College of Obstetricians and Gynecologists (ACOG) explains that a faint odor itself can be normal, but if a strong, irritating odor unlike usual has newly appeared, an infection or another problem should be suspected. That is, the key is not whether an odor exists but the change.

Normal discharge is clear or milky, and around ovulation it is clear and stretchy like egg white, and right before menstruation the amount increases—it sways with the cycle in this way. Such fluctuation is the natural result of the weakly acidic environment that vaginal lactic-acid bacteria create. In the clinic, it is not uncommon to see cases where someone mistakes normal fluctuation for abnormal and douches excessively, rather collapsing the environment.

If you want to know more about your own vulva and discharge, I recommend also reading the article dealing with normal anatomy and individual variation.

What we ask first of someone who comes complaining of discharge is not simply "do you have an odor" but questions that combine several clues. We look together at how long it has been, what the color is, whether the consistency flows like water or is sticky like cream, whether it is related to sexual intercourse, whether vulvar symptoms like pain or itching accompany it, and whether it is a recurrence.

It is hard to conclude the cause by odor alone, but the kind of odor greatly narrows the direction of the suspected condition. The table below organizes the representative patterns often encountered in the clinic. However, since actual patterns overlap and blur from person to person, the principle is to confirm by examination and testing rather than self-diagnosis.

As the table shows, the ones with strong odor are bacterial vaginosis and trichomonas, whereas candida vaginitis is rather of the kind where odor does not stand out. So if "odor" is the main complaint, the center of gravity of differentiation naturally shifts to the first two.

When odor is the main symptom, the first thing to come to mind is bacterial vaginosis. The characteristic odor expressed as "fishy smell" in textbooks is representative, and the US Centers for Disease Control and Prevention (CDC)'s vaginal discharge clinical guideline describes bacterial vaginosis as thin, uniform grayish-white discharge with a fishy smell.

Strictly speaking, bacterial vaginosis is closer to a state in which the balance has collapsed—beneficial bacteria (lactic-acid bacteria) in the vagina decrease and other bacteria increase—rather than an infection transmitted from outside. It tends to occur when the vaginal environment is disturbed by lowered immunity, fatigue, frequent douching, sexual intercourse, and so on. Characteristically, when it meets alkaline substances like soap or semen, the odor becomes stronger, so many people feel the odor more strongly right after intercourse or around menstruation.

Diagnosis is made by combining a rise in the discharge's acidity (pH), a fishy-smell test, grayish-white discharge, clue cells under the microscope, and so on. As for treatment, based on the CDC guideline, oral metronidazole 7-day therapy is the standard, and metronidazole vaginal suppository 5-day therapy or clindamycin vaginal cream are also recommended. As the original article also emphasized, partner co-treatment is usually not recommended, but if the man has symptoms, it is good to be seen together.

Bacterial vaginosis tends to recur often even when treated well. If it recurs, how to manage chronic vaginitis or the article dealing with bacterial vaginosis and Gardnerella in detail is helpful.

If, along with odor, yellowish or frothy discharge and itching accompany it, we suspect trichomonas vaginitis. Trichomonas is a sexually transmitted infection caused by a parasite called a protozoan, and unlike bacterial vaginosis, it clearly spreads between people.

The CDC explains trichomonas discharge as being large in amount, having an unpleasant odor, and possibly being yellowish, and states that it can accompany vulvar itching, burning, redness, and discomfort during urination. However, a considerable number have no distinct symptoms, so it is not uncommon for it to be confirmed only through testing.

The biggest difference from bacterial vaginosis is the necessity of partner treatment. The CDC STI Treatment Guidelines (2021) recommend that to prevent reinfection, the sexual partner be treated together at the same time. For treatment, in women metronidazole 7-day therapy or tinidazole single-dose therapy is recommended, and an important characteristic is that, because the reinfection rate is high, retesting about 3 months after treatment is advised.

Interestingly, not all vaginitis accompanies an odor. If there is white clumpy discharge with severe itching but the odor doesn't stand out, there is a high possibility it is vaginitis caused by a yeast called Candida.

ACOG explains yeast vaginitis as white clumpy discharge like cottage cheese, and states that the vaginal acidity at this time is close to the normal range. That is, it is of a different grain than bacterial vaginosis, in which acidity rises and a fishy smell accompanies it. So the complaint "it does itch but there's not much odor" becomes a quite useful clue for differentiation.

However, from clinical experience it is hard to cut cleanly between yeast vaginitis and bacterial vaginosis by odor alone, and mixed infections where both are present together are not rare either. So rather than deciding on a drug by history alone, confirming the cause by examination and testing is safe. The CDC guideline also makes clear that accurate diagnosis is difficult by history alone and that examination and testing are needed.

If you are unsure whether the discharge is within the normal range or is vaginitis, I recommend also reading the article dealing with the normal range.

The kind of odor does give clues, but connecting that clue directly to drug choice is dangerous. We often see in the clinic cases where someone bought and used yeast vaginitis medication, leaning on internet information or past experience, when it was in fact bacterial vaginosis or trichomonas.

In particular, in situations like the following, I recommend a medical visit over self-treatment.

• When it is a first-time odor·discharge change so comparison with usual is difficult
• When other symptoms like itching, pain, urinary discomfort, fever are present together
• When it recurs or does not improve even with medication
• When the sexual partner also has symptoms
• When pregnant or possibly pregnant

If you mistake an infection that needs partner treatment, like trichomonas, for yeast, you yourself may seem to improve for a while, but reinfection repeats and you end up wasting time. Connecting the signal of odor to an accurate diagnosis is, in the end, the fastest route.

The most common mistake people make to reduce odor is frequent douching. If you wash the inside of the vagina with soap or cleanser, lactic-acid bacteria rather decrease and the acidity is disturbed, which can promote bacterial vaginosis. For the vulva, gently washing with lukewarm water is enough.

Beyond that, it helps to wear breathable cotton underwear, not to leave tight clothing or a sweaty state for long, and to manage fatigue·sleep deprivation that lowers immunity. However, these lifestyle habits are, after all, preventive adjuncts, and if a strong odor and discharge change have already occurred, rather than expecting resolution by lifestyle correction alone, it is better to confirm the cause by a medical visit.

If you are curious about vaginitis prevention in general, please refer to the article organizing how to prevent vaginitis, and if recurring vaginitis is your concern, to the recurring vaginitis·uteritis item.

The odor of vaginal discharge is not something to be ashamed of and hide, but useful information the body sends. If the fishy smell has gotten stronger, you can think of bacterial vaginosis; if yellow frothy discharge and itching are together, trichomonas; if white clumps and itching without odor, yeast vaginitis. However, the principle is that actual diagnosis and treatment are confirmed through examination and testing. If you feel a change different from usual, I recommend not hesitating and getting consulted at a nearby obstetrics and gynecology clinic.

If odor or discharge changes concern you, please inquire comfortably online.

Written by: Lee Dong-hee Director · Obstetrics and Gynecology Specialist · View doctor profile

First published January 11, 2024 · Last reviewed May 30, 2026

References: US Centers for Disease Control and Prevention STI Treatment Guidelines (2021), US Centers for Disease Control and Prevention vaginal discharge clinical guideline (2021), American College of Obstetricians and Gynecologists vaginitis patient information (2024)

This article is intended to provide general health information and does not replace individual diagnosis or treatment. If you have symptoms, please consult through a medical visit.