If you've noticed a fishy odor and your first thought is "I must have a UTI," you're not the only one to make that connection. However, that distinctive smell isn't a symptom of a urinary tract infection. A fishy odor is actually the hallmark sign of bacterial vaginosis (BV), a condition that affects the vagina, not the urinary tract. The confusion is understandable, since the urethra and vagina are close neighbors. While the symptoms can sometimes seem to overlap, UTIs and BV are two very different conditions with different causes and require different approaches to feel better.
What a UTI Actually Smells Like
A urinary tract infection, or UTI, is an infection in any part of your urinary system, which includes your kidneys, bladder, ureters, and urethra [1]. Most UTIs are bladder infections, and they happen when bacteria, most commonly Escherichia coli (E. coli), travel up the urethra and begin to multiply [1]. While a UTI can sometimes change the way your urine smells, it won't be fishy. Instead, you might notice a strong, ammonia-like odor or that your urine just smells unusually potent. This is due to the presence of bacteria in the urine itself.
The signs of a UTI are almost entirely focused on urination. Think about that classic, unmistakable feeling of a burning sensation when you pee, or feeling like you have to go to the bathroom constantly, even when you know your bladder is empty. You might also notice that your urine looks cloudy or has a tinge of blood, and you could feel some pressure or cramping in your lower abdomen.
About 50-60% of women will experience at least one UTI in their lifetime, making it an incredibly common health concern [1]. The key takeaway is that the symptoms are almost exclusively urinary. Any unusual smell is coming from your urine, not from vaginal discharge.
The Real Cause of a Fishy Smell: Bacterial Vaginosis
That distinct fishy odor is the classic sign of bacterial vaginosis, the most common vaginal condition in women ages 15-44 [2]. BV is not an infection from an outside pathogen, but rather an imbalance in the vaginal microbiome. A healthy vagina is home to a community of bacteria, dominated by beneficial species like Lactobacilli. These good bacteria produce lactic acid, which keeps the vaginal environment acidic, with a pH between 3.8 and 4.5 [4]. This acidity is a natural defense mechanism that prevents the overgrowth of harmful bacteria.
BV occurs when the population of Lactobacilli decreases, allowing other types of bacteria, particularly anaerobic bacteria, to flourish. When these anaerobes multiply, they raise the vaginal pH and produce chemical compounds called volatile amines. It is these amines that are responsible for the characteristic fishy odor [2]. This smell often becomes more noticeable after sexual intercourse, because the alkalinity of semen can further increase the production of these odor-causing amines.
Beyond the smell, BV often comes with other signs, like a thin, watery discharge that might look white or grayish. Some women also experience vaginal itching or a general feeling of irritation. While it's less common than with a UTI, some might even feel a slight burning sensation during urination. Many women with BV experience no symptoms at all other than the odor [3]. While sexual activity is a risk factor for developing BV, it is not considered a sexually transmitted infection (STI) [2]. Other factors like douching or using certain scented products can also disrupt the delicate vaginal balance and contribute to BV.
UTI vs. BV: Telling the Difference
So how do you tell which one you might be dealing with? Here’s the thing: the symptoms give you pretty clear clues once you know what to look for. With a UTI, the discomfort is all about peeing. You’ll feel that tell-tale burning sensation, the frustratingly frequent urge to go, and notice your urine might look cloudy or smell strong and ammonia-like. The feeling is centered in your urinary tract.
BV, on the other hand, is all about the vagina. The fishy odor is the biggest giveaway, often accompanied by that thin, grayish-white discharge. The discomfort is more of a vaginal itching or irritation rather than pain when you pee. Think of it this way: if your main complaint is happening when you go to the bathroom, it points toward a UTI. If the main issue is a persistent odor and change in discharge, it’s pointing toward BV.
Of course, because the symptoms can sometimes be confusing and other conditions like yeast infections or STIs can have similar signs, it is always best to consult a healthcare provider for an accurate diagnosis. They can help you figure out exactly what’s going on.
Supporting a Healthy Vaginal pH
Since BV is fundamentally an issue of imbalance, restoring and maintaining a healthy, acidic vaginal pH is key to managing symptoms and preventing recurrence. A healthy vaginal ecosystem relies on a strong population of Lactobacilli producing lactic acid to keep harmful bacteria in check [4].
There are several natural approaches to support a balanced vaginal environment. Simple lifestyle habits like wearing breathable cotton underwear, avoiding douching (which flushes out good bacteria), and using only water or gentle, pH-balanced cleansers on the vulva can make a significant difference. For those experiencing the tell-tale signs of BV, products designed to restore vaginal acidity can be particularly helpful.
This is where vaginal suppositories formulated to support pH balance can come in. For instance, Neycher's Odor Be Gone suppositories use lactic acid to directly help restore the vagina's optimal acidic environment. The formula also includes soothing ingredients like aloe vera, calendula, and bromelain to comfort irritated tissues, while zinc oxide provides a gentle cleansing action and hyaluronic acid adds moisture. Used as part of a comprehensive approach to vaginal wellness, such products can help provide relief from odor and discharge while supporting an environment where beneficial bacteria can thrive again.
Ultimately, understanding what your body is telling you is the first step toward finding the right solution. While a fishy smell can be concerning, it's a clear signal that points not to a UTI, but to an imbalance in your vaginal microbiome. By addressing the root cause and supporting a healthy vaginal pH, you can effectively manage the symptoms of BV and promote long-term vaginal health. If you are experiencing any of these symptoms, it is always recommended to speak with your doctor to ensure a proper diagnosis and treatment plan.
References
[1] CDC. (2024, January 22). Urinary Tract Infection Basics. Centers for Disease Control and Prevention. https://www.cdc.gov/uti/about/index.html
[2] Kaur, H., & C. (2023, November 7). Bacterial Vaginosis. StatPearls - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK459216/
[3] Mayo Clinic. (2023, June 10). Bacterial vaginosis - Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/bacterial-vaginosis/symptoms-causes/syc-20352279
[4] Lin, Y. P., Chen, W. C., Cheng, C. M., & Shen, C. J. (2021). Vaginal pH Value for Clinical Diagnosis and Treatment of Common Vaginitis. Diagnostics, 11(11), 1995. https://doi.org/10.3390/diagnostics11111995
[5] Coudray, M. S., & Madhivanan, P. (2020). Bacterial vaginosis–A brief synopsis of the literature. European Journal of Obstetrics & Gynecology and Reproductive Biology, 245, 143–148. https://doi.org/10.1016/j.ejogrb.2019.12.035
