Bacterial Vaginosis Test

A bacterial vaginosis test is a way to diagnose bacterial vaginal infection, a common condition. A healthcare provider will take a sample of vaginal discharge. Then they’ll look at the sample under a microscope, identify a specific odor or measure the sample’s pH. If the test reveals bacterial vaginosis, you may need antibiotics.

Overview

What is a bacterial vaginosis test?

A bacterial vaginosis test is a way to diagnose a bacterial vaginal infection. It’s sometimes called a vaginal pH test or a wet mount test.

The test uses a sample of fluid from your vagina. Then a healthcare provider does one or more of the following:

  • Looks at cells in the sample under a microscope.
  • Runs tests on the fluid.
  • Sends the sample to a laboratory for analysis.
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When is a bacterial vaginosis test used?

Healthcare providers use this test to determine if you have bacterial vaginosis, a common infection.

A healthy vagina contains a lot of good bacteria and some bad bacteria. But sometimes, there’s an imbalance. When your vagina contains too much bad bacteria and not enough good bacteria, the imbalance leads to bacterial vaginosis. Symptoms may include:

Who orders bacterial vaginosis tests?

A primary care provider or gynecologist orders the test and collects the sample needed to send to the lab.

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Test Details

How does a bacterial vaginosis test work?

The first step of this test is to get a sample of fluid from your vagina. That sample can undergo several types of tests for bacterial vaginosis. The most common are:

  • Wet mount: For a wet mount, the sample of vaginal discharge is placed on a glass slide, mixed with a salt solution, then examined under a microscope. This test is also called a vaginal smear or wet prep. An expert examines the sample for bacteria, white blood cells or clue cells. These cells are found on your vaginal wall. If they have fuzzy borders, this indicates a bacterial infection.
  • Whiff test: For a whiff test, the sample of vaginal discharge is checked for odor. The healthcare provider adds a special solution to the sample. If a strong fish-like smell is detected, that can confirm bacterial vaginosis.
  • Vaginal pH: A vaginal pH test measures the level of acidity versus alkalinity of the sample of vaginal discharge. Bacterial vaginosis makes pH higher than normal.

Another, less common test uses the sample to look for the genetic material (DNA) of bacteria.

How do I prepare for a bacterial vaginosis test?

Your healthcare provider will tell you how to prepare for the test. You’ll likely have to avoid certain things for 24 hours prior, as they can interfere with results:

  • Douching.
  • Having sex.
  • Using tampons.
  • Using vaginal medicines (for example, creams to reduce itching).
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What can I expect on the day of the bacterial vaginosis test?

To collect the sample, you take off your clothes from the waist down. You may have a blanket or paper sheet to drape over your legs. Then you lie down on an exam table and place your feet in stirrups to keep your legs up and apart.

Your healthcare provider inserts a medical tool called a speculum into your vagina. The tool may be covered in lubricant (a smooth, clear gel), so it inserts smoothly with little discomfort. The speculum gently spreads your vaginal walls apart so your healthcare provider can see inside your vagina. This part of the process may cause some discomfort or a feeling of pressure and the speculum may feel cold.

Your healthcare provider inserts a long cotton swab or wooden stick into your vagina and gently scrapes a bit of fluid. Finally, the provider removes the speculum and completes the sample collection.

What can I expect after a bacterial vaginosis test?

You may have some mild soreness or very light bleeding. But you will feel better quickly, and you won’t have to restrict your activity after the test.

What are the risks of this test?

There aren’t any risks associated with a bacterial vaginosis test.

Results and Follow-Up

When should I know the results of the test?

Results from a bacterial vaginosis test performed by a healthcare professional take about one to three days.

What do the results mean?

Results of a wet mount or whiff test come back as normal or abnormal. A normal result means there is no bacterial infection. An abnormal result confirms vaginal infection.

Results of a pH test come back as a number. Bacterial vaginosis involves a pH that is higher than normal. A normal, healthy vagina has a pH of 3.8 to 4.5, which is slightly acidic. Anything above 4.5 is considered high. A high pH makes the vagina more likely to become infected.

What happens if a bacterial vaginosis test is positive?

If the results of a bacterial vaginosis test are positive, your healthcare provider may recommend treatment with antibiotics. The medication may be pills that you swallow or creams or gels that you put into your vagina. Your healthcare provider also may recommend internal or external creams to help ease the symptoms.

Treatment is especially important in people who are pregnant or are trying to become pregnant. Bacterial vaginosis can lead to pregnancy complications.

If the results of the bacterial vaginosis test are negative, your healthcare provider may run additional tests to find out what’s causing the symptoms.

Can I test for bacterial vaginosis at home?

Online vendors, pharmacies and others sell kits that allow you to test for bacterial vaginosis or measure vaginal pH at home. They can provide information about your vaginal health without a doctor’s appointment.

To test for bacterial vaginosis at home, you take a sample of your own vaginal fluid by inserting a swab into your vagina. You seal the sample in a container, then mail it to a lab. It may take the lab a few days to a week to process the sample and get results, depending on the kit you choose.

An at-home vaginal pH test includes a swab or a strip of paper you use to obtain a sample of vaginal fluid. The swab or paper will change color when it touches the vaginal fluid. You compare the color to a chart included in the test to determine the pH level. A high pH could indicate bacterial vaginosis or other vaginal infection.

If you choose to use a home testing kit, follow up with a healthcare provider to confirm the results. If the results are negative, your provider can explore other reasons for the symptoms. If the results are positive, you may need treatment with antibiotics or medications to help you manage symptoms.

A note from Cleveland Clinic

A bacterial vaginosis test is a way to diagnose bacterial infection in your vagina. It uses a sample of vaginal discharge, which can be examined in several different ways. If you have symptoms of bacterial vaginosis, talk to a healthcare provider about testing and ways to relieve symptoms. Treatment is essential in people who are pregnant or planning to become pregnant.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 11/30/2021.

Learn more about our editorial process.

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