What Is Bacterial Vaginosis?The Fishy Smell, the Discharge and What Treats It

It happens after sex, or sometimes after your shower. A smell you can’t place, sharper than usual, a little like fish. You wash again. It doesn’t help, and you start wondering if it’s you.

What it looks and smells like

The NHS³ describes an unusual discharge with a strong fishy smell, particularly after sex, and says the discharge may be greyish-white, thin and watery. OWH¹ adds that discharge can be white, gray, foamy or watery, and that some people have burning when they pee, itching or irritation. The CDC² lists the same signs.

Here’s the part that makes BV hard to catch. The NHS³ says half of women with BV don’t have any symptoms. And the CDC’s⁴ treatment guidelines call it the most common cause of vaginal discharge worldwide.

Compare that with a yeast infection, where OWH¹ describes extreme itchiness and a thick, white, cottage cheese discharge. Our article on repeat yeast infections goes through that one. If odor is your main concern, what causes vaginal odor sorts the possibilities, and discharge covers what changes are typical.

Why it happens

The NHS³ says BV stems from a change in the natural balance of bacteria in your vagina. OWH¹ says harmful bacteria outnumber the helpful ones.

The risk factors on the lists overlap:

• Sexual activity. The NHS³ says BV isn’t classed as a sexually transmitted infection, but sexual activity can trigger it. The CDC² lists new or multiple sex partners and inconsistent condom use. OWH¹ adds that the exact way it spreads is still being studied.
• Douching. Listed by the CDC² and OWH¹. The CDC’s guidelines say douching may increase the chance of relapse and has no evidence behind it for relieving symptoms.
• Perfumed products. The NHS³ lists perfumed soaps and intimate products, and IUDs.
• Pregnancy. Listed by OWH¹.

BV can happen without sex. The NHS³ says people with no sexual history can get it, though the CDC⁴ says it rarely affects people who’ve never been sexually active.

How it’s diagnosed and treated

A provider can test a sample of vaginal fluid, the CDC² says. Its guidelines describe a clinical check that looks at the discharge, its pH, the smell after a test solution is added, and cells under the microscope. That’s one reason not to guess.

Treatment is antibiotics: tablets, gel or cream, the NHS³ says. The CDC’s⁴ guidelines list regimens of metronidazole by mouth or as a gel, or clindamycin cream, running 5 to 7 days. OWH¹ says to take all of your medicine, even if symptoms disappear.

Partners. The advice differs. The CDC’s⁴ guidelines don’t recommend routine treatment of sex partners, and the CDC says male partners don’t need treatment but BV can spread between female sex partners. The NHS³ says female partners may need treatment at the same time. Ask your clinician what applies to you.

Why it comes back

The NHS³ says it’s common for BV to return, usually within a few months. The CDC² says it can return even after treatment. If you get it 4 or more times a year, the NHS says a GP may suggest a longer course of vaginal antibiotic gel. The CDC says a long run of gel twice a week for more than 3 months may reduce recurrences, though the benefit doesn’t last after you stop.

The play

Try this: strip the routine back

For four weeks, wash the area with water and plain soap only, the way the NHS³ recommends, and take showers instead of baths.

Skip perfumed soaps, vaginal deodorants, douches and antiseptics. The NHS³ lists all of them, along with smoking, as things to avoid.

Write down when the smell shows up and what’s different that day. If it persists, that note goes to your clinician.

BV and pregnancy

OWH¹ says BV is safe to treat during pregnancy, with the same antibiotics, and that testing and treatment help prevent premature birth and low birth weight. The NHS³ says complications like premature birth are possible but uncommon. If you’re pregnant and suspect BV, see your clinician instead of waiting.

When to get checked

OWH¹ says to see a provider if you suspect BV, and to follow up if symptoms persist after you’ve finished treatment.

Book an appointment if any of these fit:

• You have a new fishy smell or an unusual discharge
• You’re not sure whether it’s BV or a yeast infection
• Symptoms haven’t gone away after treatment
• It keeps coming back
• You’re pregnant and notice any of this

The smell has an explanation, and it isn’t you. Get the test, finish the course, and the shower can go back to being a shower.