What Does Bacterial Vaginosis Smell Like?

Bacterial vaginosis (BV), also known as vaginal dysbiosis, is one of the most common vaginal infections among women ages 15 to 44. It's estimated that about 29% of American women will experience it in their lifetime.

While BV is not a serious condition, it can increase the risk of contracting sexually transmitted infections (STIs), experiencing preterm labor, and causing emotional distress, which is why treatment is important.  

Read on to learn about BV symptoms, diagnosis, possible complications, and treatments.

Woman consults with gynecologist for symptoms of genitorurinary syndrome of menopause

YakobchukOlena / Getty Images

What Is Bacterial Vaginosis?

Vaginas have a variety of naturally occurring bacteria. The bacteria help maintain a moderate to high acidic (low pH) balance to protect against infections. "Bad" bacteria are usually mitigated before causing noticeable change. It's only when there are increased numbers of pathogens that BV occurs.

BV can increase the risk of contracting STIs, such as HPV (human papillomavirus), if left untreated. It can leave you vulnerable to pelvic inflammatory disease (PID), caused by bacteria spreading from your vagina to your uterus. It's also a risk factor for an increased incidence of preterm birth in pregnant women.

Symptoms 

Researchers don't fully understand the cause of BV, but a lot has to do with a woman's specific makeup (genetics). About 84% of women are asymptomatic.

Some key signs of BV are:

  • Increased vaginal pH
  • Thin white or gray discharge
  • Pain, itching, or burning in and around the vagina
  • A strong odor (commonly described as fishy)
  • Burning when peeing (dysuria)

What Does Bacterial Vaginosis Smell Like?

BV is often described as having a strong fishy odor. There's a technical reason why the smell of BV is described this way: trimethylamine. This chemical compound is why rotten fish smells, and it's also responsible for the aroma of abnormal vaginal odors.

This hallmark odor is particularly prominent after penile-vaginal sex. That's because semen reduces the acidity of the vagina, and the smell-inducing chemical compounds are more noticeable at a higher pH.

What Else Could Be Causing Vaginal Odor?

Vaginas, by nature, are prone to varying smells, especially during sexual arousal and menstruation. Other lifestyle factors such as stress, pregnancy, and sexual intercourse can also change how your vagina smells.

But certain odors warrant attention, which could signal vaginal infectionsSTIs, and sexually associated infections.

Trichomoniasis 

Trichomoniasis (trich) is the most common curable STI. It is passed through unprotected sex with a partner who has the infection. One of the common symptoms is a pungent, fishy vaginal odor accompanied by white, yellow, or greenish discharge.

Yeast Infection

Yeast infections are also caused by an overgrowth of bacteria (mainly a fungus called Candida) in the vagina. Along with extreme itchiness, yeast infections can cause changes in vaginal discharge and odor.

Menstruation

You may have noticed your menstrual cycle causes different vaginal odors, including metallic, rotten, or sweaty. Some of these are usual period blood smells and nothing to worry about. Others, like a strong fishy smell, can point to infection from a forgotten tampon. See a healthcare provider right away if you suspect this is the case.

Treatment of Bacterial Vaginosis

Treating BV is fairly easy. A short course of oral or topical antibiotics usually clears it up, as long as you follow through with the entire round of the medication. Stopping when symptoms disappear is risky, as you may develop antibiotic-resistant bacteria, making the infection recur and causing it to be more challenging to treat the next time around. Treating BV may also reduce the risk of getting other STIs.

How to Prevent Vaginal Odor

Researchers believe a complex interaction of multiple factors causes BV. There are many proven ways to keep your vagina smelling healthy.

When it comes to your sex life, keep the following in mind:

  • Practice a monogamous sexual partnership.
  • Thoroughly wash sex toys.
  • Wear condoms consistently.
  • Use unscented/unflavored lubricants and condoms.

In your daily life, you can avoid vaginal odor by:

  • Wearing breathable cotton underwear
  • Washing after sweating (working out)
  • Avoiding scented products such as feminine sprays, tampons, and soap
  • Skipping douche
  • Quitting cigarette smoking
  • Strengthening your immune system through foods or probiotics

When to See a Healthcare Provider

It's important to remember that a strange or unpleasant vaginal smell is your body's way of telling you that something is off. Do your best to set up an appointment with your healthcare provider when you notice an unusual smell or change in discharge.

Besides providing peace of mind, a healthcare provider will examine your vagina for signs of discharge. A medical professional also can test a sample of vaginal fluid to determine if BV is present or if you have another infection that needs to be treated.

BV can increase your risk of contracting STIs and pelvic inflammatory disease if left untreated.

Summary

Bacterial vaginosis (BV) is one of the most common vaginal infections among women of reproductive years. It's caused by an imbalance of good and bad vaginal bacteria, though researchers are still looking into exactly why it occurs.

While it's not a serious condition, BV can increase the risk of contracting sexually transmitted infections (STIs). Getting BV diagnosed and treated by a healthcare provider is important. Treatment of antibiotics must be completed in full to prevent recurring BV.

A Word From Verywell

Most of the time, people don't think about vaginal health until an odor or similar change develops. There's nothing to be ashamed of if you have BV, an STI, or another vaginal infection. Instead, seek proper care and take it as an opportunity to improve your long-term vaginal health routine.

Frequently Asked Questions

  • What is a yeasty smell?

    Yeasty smells are often described as tangy or sour. They're similar to fermented foods such as sourdough bread, kombucha, or Greek yogurt. The primary type of bacteria responsible for this distinct smell (which is also present in healthy vaginas) is Lactobacilli.


  • What does a healthy vagina smell like?

    A healthy vagina typically smells musky, sweaty, or a bit tangy. It should not have a strong unpleasant smell, which may be a sign that you have an infection.

  • What’s the difference between bacterial vaginosis and a yeast infection?

    Both infections are caused by an overgrowth of "bad" microbiomes in the vagina. The key difference is that the overgrowth in BV is bacterial, while the overgrowth in a yeast infection is fungal.

  • Can bacterial vaginosis come back?

    Yes. For some women, BV frequently returns, even with great vaginal health practices. A typical healthy vagina is slightly to moderately acidic. Researchers are still trying to understand why some women are more prone to high pH (low acidic) vaginal microbiomes.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Bacterial vaginosis – CDC fact sheet.

  2. Center for Disease Control and Prevention. Bacterial vaginosis (BV) statistics.

  3. Turovskiy Y, Sutyak Noll K, Chikindas ML. The aetiology of bacterial vaginosis: Aetiology of bacterial vaginosisJournal of Applied Microbiology. 2011;110(5):1105-1128. doi:10.1111/j.1365-2672.2011.04977.x

  4. Ellington K, Saccomano SJ. Recurrent bacterial vaginosisThe Nurse Practitioner. 2020;45(10):27-32. doi:10.1097/01.NPR.0000696904.36628.0a

  5. Wolrath H, Stahlbom B, Hallen A, Forsum U. Trimethylamine and trimethylamine oxide levels in normal women and women with bacterial vaginosis reflect a local metabolism in vaginal secretion as compared to urineApmis. 2005;113(7-8):513-516. doi:10.1111/j.1600-0463.2005.apm_175.x

  6. Center for Disease Control and Prevention. Trichomoniasis – CDC fact sheet.