Bacterial Vaginosis Test

What is a bacterial vaginosis test?

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

The test uses a sample of fluid (discharge) from your vagina.

When is a bacterial vaginosis test used?

Healthcare providers use this test to determine if you have bacterial vaginosis, a common bacterial 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 many bad bacteria and not enough good bacteria, the imbalance leads to bacterial vaginosis.

Some common symptoms of BV are:

• Foul-smelling vaginal discharge (often described as fish-like).
• Gray or white vaginal discharge.
• Pain, irritation or itching.
• A burning sensation when peeing.

Who orders bacterial vaginosis tests?

A primary care provider (PCP) or gynecologist orders the test and collects a sample of your vaginal discharge in their office. Then a healthcare provider does one or more of the following:

• Looks at cells in the sample under a microscope.
• Runs tests on cells in the sample.
• Sends the sample to a laboratory for analysis.

How does a bacterial vaginosis test work?

The first step of this test is to get a sample of fluid from your vagina. There are several ways providers can test that sample for BV. The most common are:

• Wet mount: For a wet mount, a pathologist puts the sample of vaginal discharge on a glass slide mixed with a solution, then examines it under a microscope. Then, they examine 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. This test is also called a vaginal smear or wet prep.
• Whiff test: For a whiff test, your provider checks the sample of vaginal discharge for an odor. They add a special solution to the vaginal fluid sample. If the result is a strong fish-like smell, 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. This test alone can’t diagnose bacterial vaginosis, so it’s often used with another testing method.
• DNA test: Also called a PCR test, this method involves checking the genetic material in the fluid sample. This test is expensive and not used as often as the other methods.

Can BV be detected in urine?

No. A urine test detects bacterial infections in your urinary tract. But providers can’t diagnose bacterial vaginosis from a sample of your pee.

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 the following for 24 hours prior, as they can interfere with results:

• Douching.
• Having sex.
• Using tampons.
• Using vaginal medicines (for example, creams to reduce itching).

What can I expect on the day of the bacterial vaginosis test?

A BV test begins like a pelvic exam. You’ll remove 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.

The steps generally involve:

• Your healthcare provider inserting 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.
• Your healthcare provider inserting a long cotton swab or wooden stick into your vagina and gently scraping a bit of vaginal fluid.
• Finally, your provider putting the sample in a sterile container, then removing the speculum.
• You putting your clothes back on and going home right after the test.

What can I expect after a bacterial vaginosis test?

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

What do the results mean?

Results of a wet mount or whiff test come back as normal or abnormal. A normal result means there’s no bacterial infection. An abnormal result means you have a bacterial infection.

Results of a pH test come back as a number. Bacterial vaginosis involves a pH that’s higher than normal. A 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 your vagina more prone to infection.

When should I know the results of the test?

Results from a bacterial vaginosis test take between one and three days. Ask your provider when you can expect results and what the next steps are.

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 may also recommend internal or external creams to help manage symptoms like pain or itching.

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

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

Can I test for bacterial vaginosis at home?

Online vendors and pharmacies 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 going to your healthcare provider’s office.

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

Your vaginal health may not be something you think of often — until you have a problem. Itching, burning or a foul-smelling odor can all be signs of bacterial vaginosis, a common vaginal infection.

A bacterial vaginosis test is a quick, painless and risk-free way to diagnose an infection in your vagina. Your provider takes a sample of your vaginal discharge and sends it to a lab for testing. If you have bacterial vaginosis, your healthcare provider may prescribe antibiotics to clear the infection.