Bacterial Vaginosis (BV) and a vaginal yeast infection, formally known as Vulvovaginal Candidiasis, are two of the most frequently diagnosed vaginal infections. Both conditions result from an imbalance in the delicate vaginal microbiome. Because the initial signs often involve a change in vaginal discharge or general discomfort, they frequently mimic each other. This symptomatic overlap leads to confusion, making accurate self-diagnosis nearly impossible and professional evaluation necessary.
Overlapping Symptoms That Lead to Confusion
The primary reason many people confuse bacterial vaginosis with a yeast infection is the shared presentation of general irritation and discomfort. Both conditions disrupt the normal, healthy vaginal environment, leading to symptoms that signal an underlying issue. This shared experience can prompt incorrect self-treatment.
Individuals often report localized itching, which can range from mild to intense. They may also experience vulvovaginal irritation or soreness, sometimes accompanied by a burning sensation. Both infections typically result in an increased volume of vaginal discharge that differs from a person’s usual pattern.
The presence of these common symptoms—irritation, itching, and abnormal discharge—often leads to the mistaken use of over-the-counter antifungal creams to treat what may be a bacterial infection. Since both conditions alter the stability of the vaginal environment, the initial discomfort often feels similar, regardless of the underlying microbial cause.
Distinctive Markers of BV Versus Yeast Infection
While many symptoms overlap, the specific characteristics of the discharge and the presence of odor are the defining factors separating bacterial vaginosis from a yeast infection. BV is caused by an overgrowth of certain anaerobic bacteria, which replaces beneficial Lactobacillus species. This microbial shift results in the production of volatile amines, which are responsible for the tell-tale symptoms of BV.
The most recognized marker of BV is a thin, watery, grayish-white or sometimes greenish discharge that carries a distinct “fishy” odor. This odor is often noticeably stronger following sexual intercourse or during menstruation. Furthermore, BV causes the vaginal pH level to elevate, typically rising above 4.5.
In contrast, a yeast infection is caused by an overgrowth of a fungus, most commonly Candida albicans, and it does not typically produce a strong odor. The discharge is usually thick, white, and clumpy, often described as having a “cottage cheese” consistency. Unlike BV, a yeast infection frequently causes more intense symptoms, including severe itching and burning, along with visible redness and swelling of the vulva.
The fungal overgrowth in a yeast infection usually maintains a normal or slightly acidic vaginal pH of 4.5 or below. The type of organism causing the imbalance—bacteria versus fungus—is the fundamental difference. Recognizing these specific markers is crucial for proper identification.
Clinical Testing and Misdiagnosis Risks
A professional diagnosis is necessary to accurately differentiate between BV and a yeast infection because self-assessment is unreliable. Clinicians use specific, objective tests to determine the exact cause. One informative test is measuring the vaginal pH level, which quickly separates the highly acidic environment of a yeast infection from the elevated pH of BV.
A healthcare provider will also perform a wet mount microscopy, examining a sample of the discharge under a microscope. For BV, the clinician looks for “clue cells,” which are epithelial cells covered in bacteria. For a yeast infection, they look for yeast buds or hyphae, the thread-like structures of the Candida fungus.
The “whiff test” is another diagnostic tool for BV, where potassium hydroxide is added to the sample, intensifying the characteristic fishy odor if BV is present. Attempting to self-treat without clinical confirmation carries significant risks, as the treatments are completely different.
Treating BV with antifungal medication will not resolve the bacterial issue and allows it to persist. Conversely, treating a yeast infection with antibiotics can inadvertently kill beneficial Lactobacillus bacteria, promoting fungal overgrowth. This incorrect treatment can lead to prolonged symptoms, condition recurrence, and contribute to antimicrobial resistance. Seeking professional testing ensures the correct medication is prescribed to effectively treat the specific pathogen.