How Do You Know if You Have BV or AV? Distinguishing Key Vaginal Infections

September 30, 2025 •

5 min read

Globally, BV affects nearly 30% of reproductive-aged women, while AV is less common but frequently misdiagnosed. Understanding how do you know if you have BV or AV? is crucial because these conditions, while both vaginal microbiome imbalances, require very different treatments.

Quick Summary

This guide details the distinct signs, causes, and diagnostic methods for bacterial vaginosis (BV) and aerobic vaginitis (AV). Knowing the differences is vital for accurate treatment and managing your vaginal health effectively.

Key Points

Symptom Differences: BV typically causes a thin, fishy-smelling discharge with minimal inflammation, while AV leads to a thick, foul-smelling discharge with significant burning, redness, and irritation.
Causative Bacteria: BV is caused by an overgrowth of anaerobic bacteria, whereas AV is caused by aerobic bacteria and is an inflammatory condition.
Professional Diagnosis is Critical: Distinguishing between BV and AV often requires a healthcare provider to perform tests, such as a vaginal pH measurement and microscopic analysis of discharge, as symptoms can overlap.
Targeted Treatment: The correct treatment depends on the specific infection. BV is typically treated with antibiotics like metronidazole, while AV may require antibiotics that target aerobic bacteria, possibly alongside topical steroids.
Prevention Strategies: Maintaining vaginal health and preventing recurrence involves avoiding douching, practicing good hygiene, and potentially using probiotics to support a healthy microbiome.
Incorrect Treatment Worsens Condition: Using a treatment intended for BV (like metronidazole) on an AV infection will likely be ineffective and could exacerbate symptoms.

Navigating the world of vaginal infections can be confusing, as many conditions share similar symptoms. The vaginal microbiome is a delicate ecosystem of bacteria, and when this balance is disrupted, infections like Bacterial Vaginosis (BV) and Aerobic Vaginitis (AV) can occur. While both can cause discomfort, their underlying causes and treatment protocols are fundamentally different. Knowing the specific indicators of each is the first step toward finding relief and restoring your vaginal health.

Understanding the Symptoms: BV vs. AV

At first glance, the signs of BV and AV may appear similar, but a closer look reveals key differences related to the type of bacteria causing the infection and the body's inflammatory response.

Symptoms of Bacterial Vaginosis (BV)

BV is an overgrowth of anaerobic bacteria, which thrive in low-oxygen environments. This is a "non-inflammatory" condition, meaning it does not typically cause the severe redness or swelling associated with AV.

Characteristic Fishy Odor: Often the most prominent sign, this odor may become more noticeable after sex or during menstruation. It is caused by specific metabolic products released by the anaerobic bacteria.
Thin, Watery Discharge: The discharge is typically milky white or grayish in color, and its consistency is notably thin and uniform.
Minimal Itching or Burning: While some women may experience mild irritation, intense itching and burning are not typical symptoms of BV alone.
No Symptoms at All: Many women with BV experience no symptoms whatsoever, making diagnosis challenging without professional examination.

Symptoms of Aerobic Vaginitis (AV)

In contrast, AV is caused by an overgrowth of aerobic bacteria, like E. coli or Group B Streptococcus, and is characterized by a significant inflammatory response.

Thick, Sticky Discharge: The discharge is typically yellow or greenish and has a thicker, sometimes sticky, consistency.
Foul or “Rotten” Odor: The smell associated with AV is often described as foul or rotten, rather than the distinct fishy odor of BV.
Significant Vaginal Inflammation: Redness, swelling, and a burning or stinging sensation are common due to the inflammatory nature of the infection.
Painful Sex (Dyspareunia): The inflammation can lead to discomfort or pain during intercourse.
Vaginal Dryness: In addition to inflammation, some women may experience increased vaginal dryness.

The Importance of Professional Diagnosis

Because symptoms can overlap, self-diagnosis is unreliable and can lead to incorrect treatment. A healthcare provider will perform a pelvic exam and take a sample of vaginal discharge to analyze. The diagnostic process often involves several steps:

Vaginal pH Testing: Both AV and BV cause the vaginal pH to rise above its normal acidic level of 4.5. However, this test alone cannot differentiate between the two or rule out other infections like Trichomoniasis.
Wet Mount Microscopy: A sample of the discharge is examined under a microscope. A BV diagnosis may reveal "clue cells"—vaginal cells coated in bacteria—and a lack of the usual Lactobacilli. An AV diagnosis will show a reduced presence of Lactobacilli and an increase in white blood cells and specific aerobic bacteria.
Whiff Test: A chemical is added to the discharge sample. A strong, fishy odor can indicate BV, although a negative test does not rule it out.
Molecular Testing: Newer, highly accurate DNA-based tests (like qPCR panels or next-generation sequencing) can precisely identify the specific bacteria present, helping to distinguish between BV and AV.

Comparison Table: BV vs. AV


Feature	Bacterial Vaginosis (BV)	Aerobic Vaginitis (AV)
Causative Bacteria	Anaerobic bacteria (Gardnerella, Prevotella, etc.)	Aerobic bacteria (E. coli, Staphylococcus aureus, etc.)
Associated Inflammation	Non-inflammatory	Inflammatory (inflammation, redness, swelling)
Vaginal Discharge	Thin, watery, milky white or gray	Thick, sticky, yellow or greenish
Vaginal Odor	Distinctive "fishy" odor	Foul or "rotten" odor
Vaginal pH	Above 4.5	Above 4.5
Additional Symptoms	Possible mild itching; many cases are asymptomatic	Burning, stinging, vaginal redness, painful intercourse
Typical Treatment	Antibiotics like metronidazole or clindamycin	Antibiotics like clindamycin, possibly corticosteroids

Tailored Treatment for BV and AV

As the causes are different, the treatments for BV and AV are not interchangeable. Using the wrong medication, such as using a BV treatment for an AV infection, can worsen the condition.

Treatment for Bacterial Vaginosis

Antibiotics: The standard treatment involves a course of antibiotics, such as oral or topical metronidazole, or oral or vaginal clindamycin. It is essential to complete the full course of medication, even if symptoms improve quickly.
Probiotics: Some evidence suggests that probiotics, specifically those containing Lactobacillus species, can help prevent BV recurrence by restoring the healthy vaginal flora.

Treatment for Aerobic Vaginitis

Antibiotics: Treatment targets the specific aerobic bacteria identified during diagnosis. Commonly used antibiotics include clindamycin or kanamycin, which can be administered orally or intravaginally.
Topical Steroids: For more severe cases, corticosteroids may be prescribed to reduce the significant inflammation.
Estrogen Therapy: In postmenopausal women with vaginal atrophy, local estrogen therapy can help restore the vaginal lining and prevent recurrence.

Preventing Recurrence and Maintaining Balance

Regardless of the type of infection, proactive steps can help maintain a healthy vaginal microbiome and reduce the risk of recurrence. General prevention strategies include:

Avoiding Douching: Douching disrupts the natural bacterial balance of the vagina, increasing the risk of both BV and AV.
Practicing Safe Sex: Using barrier methods like condoms can reduce the risk of introducing new bacteria that can disrupt the microbiome.
Maintaining Good Hygiene: Wiping from front to back after using the toilet prevents the transfer of harmful bacteria from the anus to the vagina. Washing sex toys regularly is also important.
Using Probiotics: Regular use of probiotics, especially after a course of antibiotics, can help replenish beneficial Lactobacilli.

Conclusion

While bacterial vaginosis and aerobic vaginitis both stem from an imbalance in vaginal flora, their distinct causes and manifestations mean they require different diagnostic and treatment approaches. BV is a non-inflammatory overgrowth of anaerobic bacteria often characterized by a fishy odor and thin, gray discharge. AV, by contrast, is an inflammatory condition caused by aerobic pathogens, resulting in significant irritation and a foul-smelling, yellowish discharge. The key to effective management is a proper diagnosis by a healthcare professional, as treating one condition with the medication for the other can be ineffective or even harmful. By paying attention to the specific symptoms and seeking medical advice, you can ensure you receive the correct, tailored treatment to restore your vaginal health. Here is an authoritative link from the American Academy of Family Physicians on the diagnosis and treatment of vaginitis.

Frequently Asked Questions

The primary difference in odor is that BV is typically associated with a distinctive fishy smell, which often gets stronger after intercourse. In contrast, AV can cause a foul or "rotten" odor.

Yes, it is possible to have both bacterial vaginosis and aerobic vaginitis simultaneously. Both conditions are caused by an imbalance in the vaginal microbiome, and a diagnosis requires professional testing to identify the specific pathogens.

AV is an inflammatory condition, meaning it typically causes significant inflammation, redness, and burning in the vaginal area. BV, on the other hand, is a non-inflammatory condition and does not usually cause such irritation.

No, metronidazole is not effective for treating aerobic vaginitis because it targets anaerobic bacteria, while AV is caused by aerobic bacteria. Using metronidazole for AV can make the infection worse.

A doctor will perform a pelvic exam, measure the vaginal pH, and examine a discharge sample under a microscope. They will look for key indicators like 'clue cells' for BV and an abundance of white blood cells and specific aerobic bacteria for AV.

Neither BV nor AV are considered classic sexually transmitted infections (STIs). However, sexual activity can disrupt the vaginal microbiome and increase the risk of developing BV.

You should not use over-the-counter products without a proper diagnosis. Many over-the-counter treatments are for yeast infections and will be ineffective for bacterial imbalances. Incorrect treatment can cause the condition to worsen or lead to recurrence.

Untreated BV and AV can increase the risk of more serious conditions, including pelvic inflammatory disease (PID), and complications during pregnancy. Both also increase susceptibility to other STIs.