Bacterial vaginosis: causes, symptoms and treatment

Elizabeth Morrill
Elizabeth Morrill
Published Mar 27, 2023
a white woman in a white t-shirt lays in bed on white sheets with her hands over her face in discomfort

Key Points:

  • Bacterial vaginosis (BV) is a very common condition that is caused by an imbalance of “good” bacteria (Lactobacillus) and  “bad” bacteria (anaerobes like Gardnerella vaginalis) in the vagina.
  • Common symptoms of bacterial vaginosis are a strong, fishy-smelling odor and a thin, milky discharge. Bacterial vaginosis doesn't always cause symptoms, however, so some people don’t know they have it.
  • Antibiotics are the common first-line treatment for bacterial vaginosis. Since BV symptoms can be similar to other vaginal conditions, it’s a good idea to talk to a medical provider about your symptoms to make sure you get the right treatment, especially if you’re pregnant.

We get it – the words “fishy” and “vagina” should never go together. Yet millions of people deal with the foul odor and unpleasant vaginal discharge associated with bacterial vaginosis (BV) every year.

Bacterial vaginosis is the most common vaginal issue in people with vaginas who are between the ages of 15 and 44. It affects about 30% of women during their lifetimes.

BV can be tricky to treat, especially since more than 80% of affected individuals do not have significant symptoms. Untreated BV is also linked to problems with fertility and an increased risk of sexually transmitted infection (STI), so it’s important to deal with it, even if your symptoms are mild.

And if that wasn’t enough, BV also comes back in more than 50% of cases, even after successful treatment. While it’s not possible to prevent BV, there are steps you can take to reduce your risk.

So, what is bacterial vaginosis?

Bacterial vaginosis is a condition where “good” bacteria and “bad” bacteria in the vagina are out of balance.

A healthy vagina usually has a large number of “good” bacteria called Lactobacillus. This is the same bacteria that you might see on the side of a yogurt container or in a probiotic supplement. Lactobacillus helps protect the vagina from other infections.

When there aren’t enough Lactobacillus in the vagina, other kinds of bacteria can spread and grow. The most common bacteria that can cause bacterial vaginosis is Gardnerella vaginalis.

What causes bacterial vaginosis?

Despite all the research about bacterial vaginosis, scientists still aren’t entirely sure what causes the imbalance of bacteria in the vagina.

However, researchers do know that some activities are linked to higher rates of BV. The risk of bacterial vaginosis is higher in people who:

  • Have multiple sex partners
  • Have a new sex partner
  • Have unprotected sex
  • Douche or use other irritating vaginal products
  • Smoke
  • Were assigned female at birth (AFAB) and have sex with other AFAB people (including women who have sex with other women)

BV is not sexually transmitted. You cannot get BV from sharing bedding or toilet seats or from swimming pools or hot tubs. And while BV is most common in people who are sexually active, it’s possible to get BV without engaging in sexual activities.

The signs and symptoms of bacterial vaginosis

The most common symptoms of bacterial vaginosis are:

  • A thin white, gray or greenish discharge 
  • A strong fishy odor, which may get worse after sex
  • Vaginal itching
  • Burning with urination (“peeing”)

Bacterial vaginosis doesn’t always cause symptoms. Sometimes, symptoms are very mild, or the symptoms might come and go. In fact, more than 80% of people with BV do not have any symptoms at all.

Is it bacterial vaginosis or…?

Bacterial vaginosis is not a sexually transmitted infection. But BV can have similar symptoms to some STIs, as well as other vaginal conditions like yeast infections and urinary tract infections (UTIs).

The only way to diagnose your symptoms with 100% certainty is to talk to a medical provider who can ask questions and perform tests. That being said, there are some clues about whether your symptoms could be something else:

  • Yeast infections can cause a thick, cottage-cheese type of vaginal discharge. The discharge from bacterial vaginosis is usually thinner, like milk.
  • Chlamydia can also cause discharge, but it is usually lighter and may be transparent. 
  • Urinary tract infections often cause burning with urination (peeing), which can also happen with bacterial vaginosis and other vaginal conditions. However, UTIs rarely cause any kind of vaginal discharge.

Treatments for bacterial vaginosis

Bacterial vaginosis can be treated with antibiotics. There are no over-the-counter medications that will treat bacterial vaginosis. Some over-the-counter medications, like those used for yeast infections, can actually make BV worse.

Medications for bacterial vaginosis may come as a cream or gel that you put in the vagina. Other options include tablets that you take by mouth or granules that you sprinkle over soft food and eat.

The most common medications used to treat BV are Clindamycin and Metronidazole. Other options include Tinidazole and Secnidazole.

  • Clindamycin (also available as Cleocin and Clindesse): Used as a cream that is put into the vagina. This medicine can make latex condoms less effective while it’s being used and for up to three days after you stop using it.
  • Metronidazole (also available as Flagyl and Metrogel-Vaginal): It comes as a gel that you put into the vagina or as a pill that you swallow. It can cause stomach upset, abdominal pain or nausea, so do not drink alcohol while using this medication and for three days after finishing it.
  • Tinidazole (also available as Tindamax): Taken orally as a tablet. Avoid drinking alcohol while using this medication and for three days after finishing treatment because of the way this interacts with alcohol.
  • Secnidazole (also available as Solosec): Taken as granules that are sprinkled over a soft food like applesauce, yogurt or pudding. It usually only requires one dose. Do not drink alcohol while taking this medicine and for two days after finishing it. Also, you shouldn’t breastfeed for up to four days after finishing this medicine.

Should you treat BV if you don’t have symptoms?

There are good arguments both for and against treating bacterial vaginosis when you don’t have symptoms.

Some research suggests that asymptomatic BV can get better on its own, so there’s no need to use antibiotics unless you have bothersome symptoms. Other researchers claim that BV increases the risks of STIs, miscarriage and infertility, so it should be treated in every case.

The Centers for Disease Control and Prevention currently does not recommend treating bacterial vaginosis in people who do not have symptoms, except in certain circumstances. If you have concerns about whether you should be screened or treated for BV, talk to your medical provider.

Alternatives to antibiotics for bacterial vaginosis 

Bacterial vaginosis comes back in more than 50% of people who take antibiotics. Usually, a second round of antibiotics is prescribed. Given the risk of side effects with antibiotics and the high rate of recurrence, researchers are exploring non-antibiotic options.

Currently under research are bacteria transplants from a healthy vagina to someone who suffers from recurrent bacterial vaginosis.

Probiotic supplements, which are available now, are meant to increase your “good” bacteria.

Another option is boric acid. These suppositories have antibacterial and antifungal properties. They may also help regulate the pH level of the vagina. Early research shows that boric acid suppositories might be useful when combined with other treatment options, including prescription medications.

However, it’s not a good idea to use boric acid – or any alternative treatment – without talking to a medical provider first. Here’s why: First, these products aren’t regulated by the U.S. Food and Drug Administration and could be dangerous. Second, they aren’t appropriate for every situation (including pregnancy). Third, vaginal tissue is very sensitive and can be easily harmed. [N/P] It’s also important to know that boric acid is poisonous when swallowed, and it should never be kept in an area where children or pets could reach it. Before trying any alternative options, it’s important to talk to your medical provider to make sure it’s safe and appropriate for your personal situation.

How do you prevent bacterial vaginosis?

There is no foolproof way to prevent bacterial vaginosis. This is one reason the condition is so frustrating for people with recurrent BV.

The best way to prevent BV is to avoid activities that are linked to an increased risk of developing bacterial vaginosis.

  • Do not douche or use other potentially irritating products in the vagina, including sprays, deodorants, scented tampons or pads. 
  • Practice good hygiene by always wiping front to back after using the bathroom and washing any sex toys after using them.
  • Limit the number of sex partners you have.
  • Practice safe sex, including using latex condoms or dental dams during sex. 
  • Wear cotton underwear, which can help wick away moisture that may increase bacterial growth.
  • Don’t smoke, since smoking affects the immune system.

Can probiotics prevent bacterial vaginosis?

There is no clear consensus about whether probiotic-rich foods like yogurt or supplements can prevent BV.

If you decide to add probiotic supplements to your routine, keep in mind that the dose and type of bacteria strain might impact how well these supplements work. Some research shows that probiotics with multiple types of bacteria are more effective. Talk to your medical provider before starting any new supplements and to get help identifying a brand you can trust.

Online treatment for bacterial vaginosis

If you experience symptoms of bacterial vaginosis, you have options. There are several different medications available that can help treat BV. In addition, there are lifestyle changes that can help reduce the risk of developing BV.

If you have more questions about treatment options for BV, you can talk to an online provider about your options with Dr. B. Click here to get started.


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