The fastest way to tell the difference is by smell and discharge. Bacterial vaginosis (BV) produces a thin, grayish, fishy-smelling discharge, while a yeast infection produces thick, white, odorless discharge that often looks like cottage cheese. Both cause discomfort, but the type of discomfort and the other symptoms that come with it point in different directions. Here’s how to sort through what you’re experiencing.
Discharge: The Most Reliable Clue
Discharge is the single most distinguishing symptom between the two, and it differs in color, texture, and smell.
- BV discharge is thin, watery or foamy, grayish-white, and has a noticeable fishy odor. The smell often gets stronger after sex or during your period.
- Yeast infection discharge is thick, white, and clumpy, sometimes described as looking like cottage cheese. It typically has no odor at all, or a mild bread-like smell.
If you notice a strong fishy smell, that points strongly toward BV. If there’s no unusual smell but you see thick white discharge coating the inside and outside of your vagina, a yeast infection is more likely.
How Each One Feels
Yeast infections are defined by itching. The vulva and vaginal opening can become intensely itchy, red, swollen, and sore. Sex and urination often sting or burn because the skin is irritated and inflamed. You might notice a white coating on the skin around your vagina.
BV, on the other hand, often causes surprisingly few physical symptoms beyond the discharge and odor. Some people experience mild burning during urination or light irritation, but many people with BV don’t feel much of anything. That’s one reason it frequently goes unnoticed. If intense itching and visible swelling are your main complaints, a yeast infection is the more likely cause.
What’s Actually Happening Inside
These two conditions have completely different causes, which is why they need different treatments.
A healthy vagina is kept slightly acidic (pH between 3.8 and 4.5) by beneficial bacteria that produce hydrogen peroxide and lactic acid. This acidity keeps harmful organisms in check. BV develops when those protective bacteria decline and get replaced by a mix of other bacteria. The vaginal pH rises above 4.5, becoming less acidic, and a bacterial biofilm forms on the vaginal walls that can be surprisingly stubborn to clear.
A yeast infection is caused by an overgrowth of fungus that naturally lives in the vagina in small amounts. The vaginal pH usually stays in the normal range during a yeast infection. The fungus simply outgrows its usual boundaries, often after something disrupts the local environment: antibiotics that kill off competing bacteria, hormonal changes, a weakened immune system, or high blood sugar.
Common Triggers for Each
Knowing what set off your symptoms can help you figure out which infection you’re dealing with.
BV is more common in people who douche. Douching even once a month raises the risk by about 40%, and douching within the past week roughly doubles it. Having a new sexual partner or multiple partners also increases BV risk, though BV is not considered a sexually transmitted infection. It’s a disruption of the vaginal ecosystem, not something “caught” from someone else.
Yeast infections are more often triggered by antibiotics (which kill the bacteria that keep yeast in check), hormonal shifts like pregnancy or starting a new birth control, uncontrolled diabetes, or wearing damp, tight clothing for long periods. If your symptoms started a few days into an antibiotic course, a yeast infection is a strong possibility.
What an At-Home pH Test Can (and Can’t) Tell You
Over-the-counter vaginal pH test strips are inexpensive and widely available. They measure the acidity of your vaginal secretions on a color scale, and the FDA notes they show good agreement with a doctor’s pH reading. But they have real limitations.
A high pH (above 4.5) is consistent with BV, but it doesn’t confirm it. Other things raise vaginal pH too: menstrual blood, semen, perimenopause, and other infections like trichomoniasis. A normal pH makes BV less likely and raises the possibility of a yeast infection, since yeast overgrowth doesn’t typically shift the pH. But a normal reading doesn’t rule out infection entirely.
The bottom line: a pH test can help point you in a direction, but it can’t tell you definitively which infection you have, or whether you have one at all.
Why Getting the Right Diagnosis Matters
BV and yeast infections require completely different medications, so treating for the wrong one won’t help and can make things worse.
Yeast infections are treated with antifungal medications. Mild cases often respond to over-the-counter creams or suppositories applied directly to the vagina. For faster relief, a single oral antifungal pill is also available by prescription.
BV requires antibiotics, either taken orally or applied as a vaginal gel or cream. Over-the-counter antifungal products won’t touch BV, and using them unnecessarily can further disrupt the vaginal environment. For stubborn or recurring BV, boric acid suppositories are sometimes used as a supplemental therapy.
If you’ve been treating what you assumed was a yeast infection with over-the-counter antifungals and it isn’t clearing up after a few days, there’s a good chance it’s actually BV, or something else entirely.
What Happens If BV Goes Untreated
Yeast infections are uncomfortable but rarely dangerous. They don’t typically lead to serious complications, though they can become chronic and frustrating if they keep returning.
Untreated BV carries higher stakes. It increases your susceptibility to STIs including HIV, chlamydia, and gonorrhea. Those bacterial infections can progress to pelvic inflammatory disease, which can affect fertility. During pregnancy, BV raises the risk of preterm birth and low birth weight. BV sometimes clears on its own, but treatment significantly reduces these risks.
When Partners Need Treatment
Yeast infections don’t typically require partner treatment. While it’s possible to pass yeast back and forth during sex, it’s uncommon enough that treating a partner isn’t standard practice.
For BV, the guidance has recently shifted. In late 2025, the American College of Obstetricians and Gynecologists recommended for the first time that male sexual partners of people with recurring BV be treated with a combination of oral and topical antimicrobials. For a first episode of BV, or for same-sex partners, the decision is made on a case-by-case basis. This change reflects growing evidence that the bacteria involved in BV can be shared between partners, contributing to the cycle of recurrence that makes BV so frustrating for many people.
Quick Comparison
- Smell: BV has a fishy odor. Yeast infections have little to no odor.
- Discharge: BV is thin, grayish, foamy. Yeast is thick, white, clumpy.
- Itching: Intense with yeast. Mild or absent with BV.
- pH: Elevated (above 4.5) with BV. Normal with yeast.
- Treatment: BV needs antibiotics. Yeast needs antifungals.
- Common trigger: BV is linked to douching and new partners. Yeast is linked to antibiotics and hormonal changes.