A change in vaginal odor can be hard to ignore, especially when your discharge suddenly looks different too. One potential culprit is bacterial vaginosis (BV). A nationally representative study in the U.S. found BV in 29.2% of women ages 14-49.1
If that’s the reason you’re here, the most important question isn’t how you can make the smell go away. Instead, focus on whether BV is really the right explanation or whether you have something else that needs a different treatment. BV is common and curable, but yeast infections and sexually transmitted infections (STIs) can sometimes look surprisingly similar. Here’s what to look for, why it happens, how we treat it, and what it means if it keeps coming back.
Key takeaways
- Bacterial vaginosis occurs when the normal balance of bacteria inside the vagina changes.
- A fishy odor is common, along with a thin white or gray discharge. However, BV can also cause no symptoms.
- The condition isn’t considered a classic sexually transmitted infection (STI), but sexual contact can influence the risk of infection and its recurrence.
- Since BV, yeast infections, and trichomoniasis can have similar symptoms, testing may be necessary if the exact cause isn’t known.
- Physicians can treat symptomatic BV with antibiotics, either as oral tablets or a vaginal gel.
- Recurrent BV (BV that returns after treatment) is common, and emerging data suggest treating partners may help to prevent recurrence in some patients.
What is bacterial vaginosis?
Bacterial vaginosis is an overgrowth of certain bacteria that are naturally present in the vagina. The number of the protective “good” bacteria called Lactobacillus (bacteria that help keep the vagina naturally acidic and healthy) declines, and other bacteria increase.23
That’s why BV isn’t an indication of bad hygiene. In fact, using douches to clean inside the vagina or using scented products can upset the pH and bacterial balance even more.
BV also differs from a yeast infection: BV involves bacteria. In contrast, Candida, a fungus, causes a vaginal yeast infection.
What are the symptoms of bacterial vaginosis?
Typical BV symptoms include a clear or grayish discharge and a fishy smell. The smell is more pronounced after sex. In some cases, you may have mild irritation, itching, or a burning sensation when urinating.2 Common symptoms include:
- Clear or gray vaginal discharge
- Strong, fishy vaginal odor
- Stronger odor after sex
- Mild vaginal burning or itching
- Burning when urinating
Surprisingly, BV can also happen without any symptoms at all. In the same U.S. research that revealed BV in 29.2% of women aged 14-49, 84% of women with BV had no vaginal symptoms.1
That is one reason you shouldn’t rely on symptoms alone. If you notice a change in your discharge or smell, then it might be better to seek an exam or test rather than trying to diagnose yourself.
What causes bacterial vaginosis?
The reason the balance of vaginal bacteria shifts in some women is not known at this point, but we do know that certain factors increase a woman’s chances of having BV.23 These include:
- A new sexual partner
- Multiple sexual partners
- Inconsistent condom use
- Sex with female partners
- Douching
- Menstruation
None of these alone necessarily means a person will get BV. In some cases, people may get BV without a trigger.
Another aspect that needs discussion is douching. Cleansing within the vagina is pointless and can actually damage the natural presence of bacteria within it. All we need to do is maintain good hygiene, wash with water and, if needed, use a mild, unscented cleanser on the outside.
Use of an intrauterine device (IUD) is another reported risk factor. The Office on Women’s Health notes a higher risk with an intrauterine device (IUD), especially when irregular bleeding is present.4 Centers for Disease Control and Prevention (CDC) data specifically link higher BV prevalence with copper IUDs.3 Cigarette smoking has also been associated with BV.5
Is bacterial vaginosis an STI?
BV is not considered a typical sexually transmitted infection, but sex seems to be an important factor in its development and recurrence. While BV can happen even if you’re not having sex, it’s more common among those who are sexually active.23
Just because you have BV doesn’t mean your partner has done something wrong. Also, BV doesn’t tell you when the bacterial imbalance started or what caused it.
What has changed is our knowledge of recurrent BV. In 2025, the American College of Obstetricians and Gynecologists (ACOG) revised its recommendations to support considering concurrent sexual-partner treatment in certain adults with recurrent symptomatic BV.6 This reflects growing evidence that BV-associated bacteria can be transferred between partners.
In a 2025 randomized trial, 35% of women who were simultaneously treated with their partners experienced BV relapse within 12 weeks, as opposed to 63% of women whose male partners were not treated.7
This doesn’t mean partners must always be treated. Partner therapy does, however, have its place when BV keeps recurring.
Is it BV, a yeast infection, or trichomoniasis?
You cannot always tell from discharge alone. BV, vaginal yeast infections, and trichomoniasis (a sexually transmitted infection caused by a tiny parasite) can overlap, although certain patterns make one condition more likely than another.8
| Feature | Bacterial vaginosis | Yeast infection | Trichomoniasis |
| Discharge | Usually thin, white or gray | Often thicker or curdy | May be thin, yellowish, greenish, white, or clear |
| Odor | Fishy odor is common | Strong odor is less typical | Unusual or fishy odor may occur |
| Itching | Usually mild or absent | Often prominent | Can occur |
| Burning | Sometimes | Common | Can occur |
| STI | No | No | Yes |
If itching is intense and discharge is thick, yeast becomes more likely. If the main change is thin discharge with a fishy odor, BV moves higher on the list. But these are clues, not a diagnosis.
Here is why using over-the-counter (OTC) yeast medication repeatedly for any discharge changes isn’t always helpful. Also, antifungal medication will not treat BV.
Can bacterial vaginosis get worse during your period?
BV can become more noticeable during your period.3 However, your vaginal odor may temporarily shift due to menstrual blood, so having a different smell on the same day of your period doesn’t necessarily indicate BV.
A persistent fishy odor and a thin gray vaginal discharge even when your period is finished is more suggestive of BV and should be discussed with your OB-GYN.
Can bacterial vaginosis cause complications?
Yes. Ongoing or untreated BV is associated with certain reproductive and sexual-health risks. Individuals with BV are at greater risk of catching STIs such as chlamydia, gonorrhea, trichomoniasis, and HIV.3
CDC recommends that women with BV should be tested for HIV and other STIs.3 This doesn’t imply that if you have BV, then you must have an STI. It simply means the problems can happen together, and testing helps us avoid missing one.
BV has also been linked to pelvic inflammatory disease or PID (an infection of the female reproductive organs, usually caused by bacteria spreading upward from the vagina or cervix) and a greater risk of complications from certain gynecological procedures.3
What does bacterial vaginosis mean during pregnancy?
Any symptoms that may be BV should be checked during pregnancy rather than left unattended or managed at home. Experiencing symptoms of BV while pregnant is linked with premature rupture of membranes, preterm delivery, uterine infection, and uterine lining infection following delivery.3
Therefore, CDC recommends actively treating only symptomatic pregnant women with BV.3
Routine screening is different. Testing every pregnant person who has no symptoms solely to prevent preterm birth has not shown consistent benefit and is not routinely recommended for that purpose.
How is bacterial vaginosis diagnosed?
Your healthcare provider will usually diagnose BV based on your symptoms and may take a sample of your vaginal discharge, observe the color and smell of the vaginal discharge, or measure the pH level in the vagina.38
- Thin, evenly distributed vaginal discharge
- Vaginal pH above 4.5
- Clue cells (vaginal cells coated in bacteria that are visible under a microscope)
- A characteristic fishy odor during testing
The lab can also identify which bacteria are present or perform molecular testing that detects BV bacteria.
If a speculum is required, a speculum can be slipped gently into the vagina to view the vaginal walls and cervix and to obtain a sample.9
Not all vaginal discharge requires a full examination. Which tests you’ll need will vary based on your symptoms and medical history.
How is bacterial vaginosis treated?
Symptomatic bacterial vaginosis is treated with prescription antibiotics, most often metronidazole or clindamycin, as tablets, a vaginal gel, or a cream. Your provider chooses the medication, form, and length of treatment based on your history, pregnancy status, and what has been tried before.3
| Medication | Form | CDC regimen |
| Metronidazole | Oral | 500 mg twice daily for 7 days |
| Metronidazole 0.75% | Vaginal gel | 5 g once daily for 5 days |
| Clindamycin 2% | Vaginal cream | 5 g at bedtime for 7 days |
| Clindamycin | Oral | 300 mg twice daily for 7 days |
| Clindamycin | Vaginal ovules | 100 mg at bedtime for 3 days |
| Secnidazole | Oral granules | 2 g as a single dose |
| Tinidazole | Oral | 2 g once daily for 2 days, or 1 g once daily for 5 days |
The first three are CDC-recommended regimens; the remaining options are CDC-listed alternatives.3
Remember, self-treatment isn’t the ideal approach. Your treatment depends on your individual factors and should only be decided by your healthcare provider.
Metronidazole and tinidazole labels advise avoiding alcohol during treatment and for a short period afterward. Recent evidence suggests the interaction is less common than once thought, but follow your prescriber’s and the label’s instructions.3
Also, clindamycin vaginal cream is oil-based, so the medication can potentially weaken latex contraceptive barriers for up to 72 hours after treatment ends.3
What if bacterial vaginosis keeps coming back?
Recurrent infection can happen after successful treatment. But it does not mean that you took the medication wrong or that it was your fault. In fact, ACOG reports that up to 66% of women may have a recurrence within a year of initial treatment.6
In recurrent cases of BV, a successive standard course of antibiotic therapy may be used or, in individuals with recurring episodes, a longer suppressive therapy.3
Recurrent BV is also where current partner-treatment guidance becomes particularly relevant. If episodes keep returning, discussing your sexual partner or partners with your clinician is now an important part of the conversation.67
Can you reduce the chance of recurrence?
While there is no guaranteed way to prevent BV, a few habits can help maintain the health of the vagina and address known risk factors.23
- Do not douche
- Avoid fragranced products intended to clean or deodorize inside the vagina
- Complete prescribed treatment even if the odor or discharge improves earlier
- During treatment, follow your clinician’s instructions regarding sex and condom use
- If BV is recurrent, ask whether partner treatment is appropriate
Probiotics are heavily marketed for “vaginal balance,” but currently available probiotic products have not been established as a replacement for antibiotic treatment for BV.3
When to see a doctor?
If you develop a new, persistent odor, discharge pattern, or irritation, seek care, especially since BV can be confused with yeast infections and STIs. Book an appointment with your OB-GYN if:
- You have a persistent fishy odor or unusual discharge for the first time
- Symptoms continue after treatment
- BV seems to keep returning
- You are pregnant and develop symptoms of BV
- You develop pelvic or lower abdominal pain
- Sex becomes painful
- You have bleeding between periods or after sex
- You have genital sores or significant burning when urinating
- You have treated yourself for yeast, but the symptoms are not improving
Seek emergency care if:
Frequently asked questions
No. BV isn’t proof of infidelity. Sex can affect the bacteria in your vagina, but a BV diagnosis tells us nothing about when or why you developed the imbalance.
Yes. BV can be acquired without vaginal sex, but it is more common in sexually active individuals.
Occasionally, BV will resolve on its own. But if you do have symptoms, CDC advises you to get checked and treated for BV, as it can be mistaken for other vaginal infections and has other health implications.
No. Yeast medications are antifungal medications. They are not an effective way to treat the bacterial imbalance caused by BV.
If possible, abstain from having sex during treatment or use a condom. Certain vaginal clindamycin preparations may compromise latex barrier contraception, so be sure to read the ‘Instructions for Use’ for the medication you are prescribed.
Probiotic products are not yet proven to be effective substitutes for standard antibiotic treatment. Efforts are being made to develop alternative treatments to restore healthy vaginal bacteria.
BV recurrence is common because it is possible that the vaginal bacteria could again shift after treatment. Multiple recurrences may require a different management strategy, and current ACOG guidance states that partner treatment may be considered in some instances.
No established evidence shows that yogurt or apple cider vinegar cures BV.
Boric acid is not a first-line treatment for BV. For women with multiple recurrences, CDC includes vaginal boric acid as one part of a specific multi-step treatment approach; it should not be used as a stand-alone self-treatment.
BV has not been proven to directly cause infertility. However, BV is associated with infections and pelvic inflammatory disease (PID), which can damage the fallopian tubes and make it harder to become pregnant.
Last medically reviewed on
References
Our commitment to accuracy is paramount; we use high-quality sources, including peer-reviewed studies, to support the facts in our articles. Learn more about our Editorial Process.
- Koumans, E. H., Sternberg, M., Bruce, C., McQuillan, G., Kendrick, J., Sutton, M., & Markowitz, L. E. (2007). The prevalence of bacterial vaginosis in the United States, 2001–2004: Associations with symptoms, sexual behaviors, and reproductive health. Sexually Transmitted Diseases, 34(11), 864–869. doi.org
- Centers for Disease Control and Prevention. About bacterial vaginosis (BV). Updated December 11, 2023. cdc.gov
- Centers for Disease Control and Prevention. Bacterial vaginosis. Last reviewed July 22, 2021. cdc.gov
- Office on Women's Health. Bacterial vaginosis. Last updated May 31, 2022. womenshealth.gov
- StatPearls. Bacterial vaginosis. Last updated November 7, 2025. NCBI Bookshelf. ncbi.nlm.nih.gov
- American College of Obstetricians and Gynecologists. ACOG recommends concurrent sexual partner treatment for recurrent bacterial vaginosis for the first time. Published October 17, 2025. acog.org
- Vodstrcil, L. A., Plummer, E. L., Fairley, C. K., Hocking, J. S., Law, M. G., Petoumenos, K., et al. (2025). Male-partner treatment to prevent recurrence of bacterial vaginosis. The New England Journal of Medicine, 392(10), 947–957. doi.org
- American College of Obstetricians and Gynecologists. Vaginitis. Last updated December 2025. acog.org
- American College of Obstetricians and Gynecologists. Pelvic exams. Last reviewed April 2026. acog.org
- American College of Obstetricians and Gynecologists. Pelvic inflammatory disease (PID). Last reviewed May 2026. acog.org
- American College of Obstetricians and Gynecologists. Ectopic pregnancy. Last reviewed April 2026. acog.org
Update history
Our team monitors the health and wellness space to keep articles current.
Current version (September 24, 2026) — Medically reviewed by Dr. Sadaf Iftikhar, MBBS, FCPS. Written by Dr. Aqsa Munir, MBBS.
