Bacterial vaginosis (BV) and yeast infections are both common vaginal conditions, but they have different causes, different symptoms, and require different treatments. The quickest way to tell them apart is by discharge: BV typically produces thin, grayish, fishy-smelling discharge, while a yeast infection causes thick, white, odorless discharge with intense itching. Getting this distinction right matters because treating the wrong one won’t help, and may actually make things worse.
What Causes Each Condition
BV and yeast infections both involve disruptions to the vaginal microbiome, but they go in opposite directions. BV is a bacterial overgrowth. The vagina naturally contains a mix of bacteria, with beneficial species keeping everything in balance. When that balance tips and harmful bacteria outnumber the helpful ones, BV develops. It’s not caused by a single invading organism but by a shift in the whole bacterial community.
A yeast infection, on the other hand, is a fungal overgrowth. A small amount of yeast (most commonly Candida) lives in the vagina normally. When conditions change and yeast multiplies beyond what the body can keep in check, you get an infection. Antibiotics are actually one of the most common triggers, because they wipe out the bacteria that normally keep yeast in line. Hormonal changes, a weakened immune system, and high blood sugar also increase risk.
How Symptoms Compare
The two infections feel quite different once you know what to look for.
BV symptoms: The hallmark is a thin, grayish or white discharge that often looks foamy and has a noticeable fishy smell, especially after sex. Some people have mild irritation, but many have no itching at all. In fact, up to half of people with BV have no symptoms and only find out through a routine exam.
Yeast infection symptoms: Discharge is thick, white, and clumpy, often compared to cottage cheese. It typically has no smell. The dominant symptom is itching and irritation around the vulva and vaginal opening, which can range from mildly annoying to severe. You may also notice redness, swelling, and a burning sensation during urination or sex. A white coating in and around the vagina is another common sign.
The overlap between these two conditions is smaller than most people assume. If you have strong itching with thick white discharge, a yeast infection is more likely. If the main issue is an unusual smell with thin discharge, BV is the more probable cause.
Why Self-Diagnosis Often Goes Wrong
Despite the distinct symptom profiles, people frequently misidentify which infection they have. A study of people buying over-the-counter antifungal creams at a pharmacy found that when researchers offered them same-day clinical exams, 50% actually had a different infection than they thought. Twenty percent had both BV and a yeast infection at the same time.
This is a real problem because the treatments are completely different. Using an antifungal cream for BV won’t do anything, and the underlying bacterial imbalance can worsen. Vaginal pH can help clinicians distinguish between the two: a pH of 4.5 or above points toward BV, while yeast infections typically occur at the lower, more acidic pH that’s normal for the vagina.
Risk Factors for Each
The risk factors diverge in ways that reflect their different causes.
BV is strongly linked to sexual activity, though it is not classified as a sexually transmitted infection. Having new or multiple sex partners, not using condoms, and douching all raise the risk by disrupting vaginal bacterial balance. BV is more common when both sexual partners are female. It rarely affects people who have never had sex and occurs most often during the reproductive years, when hormonal fluctuations make the bacterial environment more vulnerable to shifts.
Yeast infections have a broader set of triggers. Recent antibiotic use is one of the biggest, since antibiotics don’t distinguish between harmful bacteria and the beneficial ones that keep yeast in check. Pregnancy, hormonal birth control, uncontrolled diabetes, and anything that suppresses the immune system can also set the stage. Wearing tight, non-breathable clothing or staying in wet swimwear creates the warm, moist environment yeast thrives in.
Treatment Differences
This is where the distinction between these two infections has the most practical impact. Yeast infections can often be treated with over-the-counter antifungal creams or suppositories, like miconazole (sold as Monistat) or clotrimazole. These are available at any pharmacy without a prescription, and mild yeast infections often clear up within a few days of treatment.
BV always requires prescription medication. Because it’s a bacterial overgrowth, antifungals are useless against it. Treatment typically involves a course of prescription antibiotics taken either orally or applied as a vaginal gel or cream, usually lasting five to seven days. There is no effective over-the-counter option for BV, so if you suspect you have it, you’ll need to get tested and treated by a healthcare provider.
For people who experience both infections at the same time (mixed vaginitis), treatment needs to address both the bacterial and fungal components. Vaginal boric acid suppositories are sometimes used in recurrent or mixed cases as a longer-term maintenance strategy, though this approach should be guided by a clinician.
Can You Have Both at Once?
Yes, and it’s not rare. That pharmacy study found that 20% of people who came in with vaginal symptoms had both BV and a yeast infection simultaneously. This is one reason why symptoms can sometimes feel confusing or not match the “textbook” description of either condition alone. If you’ve treated one infection and your symptoms aren’t fully resolving, a co-infection is worth considering.
Treating BV with antibiotics can also trigger a yeast infection afterward, since the antibiotics disrupt the bacterial balance that keeps yeast in check. Some providers will recommend a preventive antifungal alongside BV treatment for people who are prone to yeast infections.
What Happens if BV Goes Untreated
Yeast infections are uncomfortable but rarely lead to serious complications. BV carries more significant risks if left untreated. It increases susceptibility to sexually transmitted infections, including HIV, and can cause complications during pregnancy such as preterm birth and low birth weight. For anyone undergoing gynecological procedures like an IUD insertion or a hysterectomy, untreated BV raises the risk of post-procedure infection.
BV also has a frustrating tendency to recur. More than half of people treated for BV experience a recurrence within 12 months. Recurrence is more common in people with ongoing risk factors like douching or inconsistent condom use, and it sometimes requires longer or repeated courses of treatment to bring the vaginal microbiome back into a stable balance.
Quick Reference: BV vs. Yeast Infection
- Discharge: BV produces thin, grayish, fishy-smelling discharge. Yeast infections cause thick, white, odorless discharge.
- Primary symptom: BV’s main signal is odor. A yeast infection’s main signal is itching.
- Cause: BV is bacterial overgrowth. Yeast infections are fungal overgrowth.
- Treatment: BV requires prescription antibiotics. Yeast infections can often be treated over the counter.
- Vaginal pH: BV raises pH to 4.5 or above. Yeast infections occur at normal acidic pH levels.
- Co-occurrence: About 20% of symptomatic people have both at the same time.