8 Reasons Your Vagina Has a Fishy Odor, and What to Do About It

Bacterial vaginosis is the most common cause of fishy vaginal odor.[1] It happens when the natural balance of bacteria in your vagina gets thrown off — specifically, when there's an overgrowth of certain bacteria (like Gardnerella vaginalis) that crowd out the protective lactobacillus bacteria that keep your vaginal pH in check.[2]

The fishy smell from BV often gets stronger after sex or during your period.[1] Other signs include:

• Thin, grayish-white discharge
• Itching or irritation around the vagina
• Burning when you pee

Trichomoniasis (also called "trich") is one of the most common sexually transmitted infections in the world and a common cause of fishy vaginal odor.[3] It's caused by a tiny parasite called Trichomonas vaginalis, passed through sexual contact.

The discharge from trich is often frothy or foamy with a strong, unpleasant fishy smell.[3]3 You might also notice:

• Yellow-green or gray discharge
• Intense itching, burning, or soreness around the vagina
• Pain when you pee or have sex

A tampon left in too long — or a condom that slipped off during sex — is a surprisingly common cause of a sudden, intense fishy or foul smell.[5] Bacteria thrive in the warm, moist environment of the vagina when a foreign object is present, which can produce a very strong odor quickly.

This is usually the culprit if the smell came on suddenly and is particularly strong, especially right after your period. Other signs include unusual discharge (sometimes greenish or brown) and general discomfort.

If you suspect a retained tampon, see a doctor as soon as possible. They can locate and remove it safely. In some cases, a short course of antibiotics may be needed to clear up any secondary infection.[5]

Pelvic inflammatory disease is an infection of the uterus, fallopian tubes, and ovaries. It's most often caused by untreated gonorrhea or chlamydia, though other bacteria can trigger it too.[6]

PID can cause an abnormal discharge with an unpleasant odor — sometimes fishy. Other symptoms include:

• Pelvic or lower abdominal pain
• Fever or chills
• Pain during sex
• Bleeding between periods

The groin has a high concentration of apocrine sweat glands — the type that produce a thicker sweat that can take on an odor when it interacts with bacteria on the skin.[7] This is different from the internal odor caused by infections like BV.

After a workout or a hot day, you might notice a stronger smell that isn't coming from inside the vagina itself, but from the surrounding skin. This is completely normal.

A shower or a gentle rinse of the external vulva (the outer area) with plain water is usually all it takes to resolve this. Avoid using soap inside the vaginal opening asthe vagina is self-cleaning and doesn't need it.

Semen is naturally alkaline (pH around 7.2–8.0), while the vagina is normally acidic (pH around 3.8–4.5).[8] After unprotected sex, semen temporarily raises the vaginal pH, which can disrupt the natural bacterial balance and cause a temporary fishy odor.

This is usually short-lived because your vagina rebalances on its own within a few hours. But if the smell persists for more than a day or two, or if you notice discharge changes, it could be a sign that BV or another infection has developed.

Using condoms consistently can help maintain vaginal pH and reduce your risk of BV and other infections.

Douching, scented soaps, vaginal deodorant sprays, and scented wipes all disrupt the vagina's natural bacterial environment, which is exactly the environment that prevents infections like BV.[9] Ironically, trying to cover up or eliminate vaginal odor with these products can actually make the problem worse.

The vagina is a self-cleaning organ. It produces discharge specifically to flush out bacteria and maintain a healthy pH. You don't need to clean inside it.

For external cleaning, plain water is all you need. If you use soap on the vulva, choose an unscented, gentle option and keep it on the outside only.

What you eat and drink can affect your vaginal odor. Foods like fish, asparagus, garlic, and onions can temporarily alter body odor — including vaginal scent.8 Dehydration concentrates the compounds in your sweat and urine, which can also contribute to stronger odors.

In rare cases, a genetic condition called trimethylaminuria (also known as "fish odor syndrome") causes the body to produce excess trimethylamine — a compound that smells strongly of fish — due to an enzyme deficiency.[10] People with trimethylaminuria may notice a pervasive fishy smell from their sweat, urine, breath, and vaginal area. It's uncommon, but worth knowing about if you've ruled out infections and the smell persists despite good hygiene.

If you suspect trimethylaminuria, a doctor can diagnose it with a urine test and provide dietary guidance to help manage symptoms.

Treatment depends on what's causing the smell:

See a doctor if:

• The fishy smell is strong, persistent, or getting worse
• You notice unusual discharge (especially gray, green, or yellow)
• You have itching, burning, or soreness
• You have pelvic pain or pain during sex
• You have a fever
• You recently had unprotected sex or a new partner
• You might have left a tampon or other object in place
• You're pregnant

• Skip the douche. Your vagina cleans itself. Douching disrupts the natural bacterial balance and increases your risk of BV and other infections.
• Use condoms consistently. Condoms help maintain vaginal pH and reduce the risk of STIs like trichomoniasis.
• Get tested regularly. Many infections that cause odor — including trich and BV — have no symptoms. Regular testing is the only way to catch them early.
• Change tampons every 4–8 hours. Always make sure you've removed the last tampon before putting in a new one.
• Wear breathable cotton underwear. Cotton wicks moisture and reduces the warm, damp conditions that bacteria love.
• Stay hydrated. Adequate hydration helps dilute compounds that can contribute to body odor.
• Use unscented products around the vulva. Avoid scented soaps, sprays, wipes, and pads near the vaginal area.

Is it normal for my vagina to have some odor?

Can BV go away on its own?

Can I get BV without being sexually active?

Why does the smell get worse after sex?

Will antibiotics for BV or trich affect my birth control?

A fishy vaginal odor is often a sign of an infection — and the most common culprits, like BV and trichomoniasis, are very treatable once identified. But because many of these infections have no other symptoms, testing is often the only way to know for sure what's going on.

Everlywell's at-home STD test screens for trichomoniasis along with other common STIs — including chlamydia, gonorrhea, syphilis, and hepatitis C. Collect your sample privately at home, mail it to a certified lab, and get secure results online within days.

If you already have symptoms and want answers fast, Everlywell also offers online STI treatment consultations in 2 hours or less. A licensed provider can review your symptoms — including BV and trich — and send a prescription directly to your pharmacy if appropriate.