Why does my vagina smell fishy? Gyno's explain the most likely causes

• A fishy-smelling vagina is most often caused by bacterial vaginosis, an overgrowth of bacteria.
• You can treat bacterial vaginosis with oral antibiotics or antibiotics that you insert into your vagina.

It's completely normal for your vagina and discharge to have some sort of mild scent.

But if you start to notice that your vagina has an unpleasant, fishy smell this is a sign that something's off down there –– especially if you're experiencing other symptoms like unusual discharge alongside the odor.

A fishy-smelling vagina could be caused by bacterial vaginosis, perspiration, or trichomoniasis. But there are other conditions that cause odor ranging from sour to foul.

Here are three reasons for a fishy vaginal odor and what to do about it.

1. Bacterial vaginosis

Bacterial vaginosis is the main culprit for a fishy-smelling vagina, says Dr. Marilyn Jerome, an OB-GYN at Foxhall OB-GYN Associates.

This is a condition where there are too many "bad" bacteria, which leads to a disruption of the healthy natural flora, or bacteria, in the vagina.

Aside from the fishy smell, other symptoms of bacterial vaginosis are:

• Vaginal discharge that's thin, gray, green, or white
• Itchy vagina
• Burning when you pee

You may be more likely to get bacterial vaginosis if you:

• Douche
• Do not use condoms
• Have new or multiple sex partners

How to treat it: Treatment involves reducing the amount of bad bacteria in the vagina with antibiotics. Jerome says that your doctor can prescribe you antibiotics that you insert into your vagina like Clindamycin or oral antibiotics like metronidazole available.

2. Sweating

"Occasionally, sweat mixing with the vaginal flora can lead to a fishy odor," says Dr. Felice Gersh, an OB-GYN and the founder/director of the Integrative Medical Group of Irvine.

So, if you sweat excessively, especially if you stay in sweaty underwear and clothes for a prolonged period of time, this can cause a fishy smell.

Gersh says that you may also experience itching and irritation, along with the unusual smell.

How to treat it: Some quick lifestyle changes can help fix this issue. Gersh recommends that you:

• Bathe daily
• Use warm water and a mild cleanser to gently clean the vulva
• Wear breathable cotton clothes
• Don't stay in sweaty clothes
• Avoid thongs

3. Trichomoniasis

Trichomoniasis is a sexually transmitted infection caused by a parasite that can result in frothy discharge with a foul, fishy odor, says Gersh.

It can result in other symptoms including:

• Increased vaginal discharge that's thin and gray, green, white, or yellow
• Lower belly discomfort
• Painful urination
• Painful sex

While it's possible for other STIs like chlamydia or gonorrhea to cause vaginal odor, Jerome says it's not common, since these STIs are more likely to be asymptomatic versus trichomoniasis.

How to treat it: The treatment is antibiotics. Your doctor will either give you a large dose of antibiotics or multiple lower doses to ensure that the infection clears up.

In order to prevent becoming reinfected, your current sexual partner or partners must receive treatment, as well.

Additionally, to prevent reinfection in the future, Gersh recommends using condoms to lessen your risk of trichomoniasis and other STIs.

Other reasons for an unfamiliar vaginal odor

If your vaginal odor smells unpleasant — but not necessarily fishy — it could signal other irregularities. Here are some things that can cause a foul vaginal odor.

1. Vaginal intercourse with ejaculation and no condom

Gersh says if you have unprotected sex and someone ejaculates inside of your vagina, the semen can create an environment where your vaginal bacteria can produce an odor that smells chlorine-like.

This is related to a chemical reaction between the vaginal microbes and an altered vaginal pH due to the pH of semen. The average pH of semen is between 7.2 and 7.8, whereas the average pH of the vagina is more acidic, ranging from 3.8 to 5.0.

How to treat it: The odor should pass on its own. How quickly it passes will depend on the individual. If the smell lingers for more than a day, it's possible that the semen aggravated an underlying condition like bacterial vaginosis that you may need antibiotics for.

Regardless, you may want to see your OB-GYN for STI testing if you're having unprotected sex with an unfamiliar partner.

2. Foreign object stuck in the vagina

If you've accidentally left something inside your vagina for a prolonged period of time, like a forgotten tampon, condom, or sex toy, this can result in a strong, foul-smelling discharge, Jerome says.

You may also have pelvic pain or vaginal bleeding. Foreign bodies can also be a breeding ground for bacteria, increasing your risk of infection.

How to treat it: Simply removing the object from your vagina should be enough to resolve the problem and get you feeling back to normal, says Jerome. Your OB-GYN can help fully remove any foreign object and assess for any potential infection.

3. Cancer

While it's far more likely your vaginal odor is due to one of the above causes, Jerome says cancer is a very rare but possible reason for a foul vaginal odor, especially if you haven't visited your OB-GYN for screenings in many years.

This can be due to either cervical cancer or vaginal cancer.

Symptoms of cervical cancer are:

• Bleeding after menopause
• Bleeding between periods
• Bleeding after sex
• Heavy, long periods
• Large amount of bloody or watery discharge

Symptoms of vaginal cancer are:

• A mass in the vagina
• Constipation
• Pain during urination
• Pain during sex
• Pelvic pain
• Unusual discharge

How to treat it: If cancer is the confirmed diagnosis, treatment will depend on how advanced the cancer is. Common treatment options are surgery, chemotherapy, and radiation.

Insider's takeaway

Whether the smell is fishy or foul and strong, you should address any persistent bad odor outside of your norm, since it may be a sign of an infection or condition that requires medical attention.

It's important to see your OB-GYN so you receive the correct diagnosis and subsequent treatment for your condition.