Bacterial vaginosis discharge is typically thin, watery, and white to gray in color, with a consistency the CDC describes as “milklike.” It coats the vaginal walls smoothly rather than clumping or forming thick patches. While you won’t find clinical photographs in most medical resources (and photos online are unreliable for self-diagnosis), knowing the specific visual and sensory characteristics can help you recognize what you’re dealing with.
What BV Discharge Looks Like
The hallmark of BV discharge is how uniform and thin it appears. Unlike the thicker, clumpier discharge of a yeast infection, BV discharge has an even, almost liquid texture that spreads in a smooth layer. The color ranges from off-white to gray, though it can also appear yellowish or even slightly greenish in some cases. It tends to be more noticeable than normal discharge simply because there’s more of it.
The other defining feature isn’t visual at all: it’s the smell. BV produces a distinct fishy odor caused by chemical compounds called biogenic amines, specifically putrescine, cadaverine, and trimethylamine. This smell often becomes stronger after sex, because semen raises the vaginal pH and releases more of those compounds. Many people notice the odor before they notice any change in how the discharge looks, which is why smell is one of the primary diagnostic markers.
How Doctors Confirm It’s BV
A diagnosis typically requires at least three of four clinical signs. The first is that characteristic thin, homogeneous discharge. The second is a vaginal pH above 4.5 (normal is 4.0 to 4.5, maintained by healthy lactobacilli bacteria). The third is the fishy odor, which doctors can intensify in the office by adding a potassium hydroxide solution to a sample. The fourth is the presence of “clue cells” under a microscope: normal vaginal skin cells that appear stippled or studded with bacteria clinging to their edges, giving them a grainy, irregular border instead of a clean outline.
You can’t see clue cells without a microscope, and you can’t reliably measure your own pH, which is why visual identification alone isn’t enough for a definitive answer. But the combination of thin gray-white discharge plus a fishy smell is distinctive enough that most people who’ve had BV before can recognize a recurrence.
BV vs. Yeast Infection vs. Trichomoniasis
These three conditions are the most common causes of abnormal vaginal discharge, and each looks and feels noticeably different.
- BV discharge is thin, smooth, white-to-gray, and fishy-smelling. It generally causes discomfort rather than pain, and there’s usually no redness or swelling around the vaginal opening.
- Yeast infection discharge is thick, white, and clumpy, often compared to cottage cheese. It has no strong odor but comes with intense itching, redness, and sometimes burning during sex or urination. Visible swelling around the vulva is common.
- Trichomoniasis discharge tends to be frothy or bubbly, yellow-green in color, and may also have an unpleasant smell. It’s a sexually transmitted infection and often causes irritation, soreness, and pain during urination.
The quickest way to tell BV apart from a yeast infection at home: if the discharge is thin and smells fishy, it’s more likely BV. If it’s thick, clumpy, and odorless with significant itching and redness, a yeast infection is more probable.
When the Smell Gets Worse
Many people with BV notice that the odor fluctuates. It tends to intensify after unprotected sex because semen is alkaline (pH around 7.2 to 8.0), which pushes the already-elevated vaginal pH even higher and triggers a stronger release of those fishy-smelling amines. Menstrual blood has a similar effect, since its pH is also above the normal vaginal range. Some people first become aware of BV specifically because they notice an odor during their period or after intercourse, even if the discharge itself seemed unremarkable.
What Causes the Change in Discharge
BV happens when the balance of bacteria in the vagina shifts. Normally, lactobacilli dominate and keep the environment acidic (pH 4.0 to 4.5), which suppresses the growth of other organisms. When anaerobic bacteria overgrow and replace those lactobacilli, the pH rises above 4.5, the protective acidity drops, and the result is that thin, odorous discharge. It’s not a sexually transmitted infection, though sexual activity can be a trigger. Douching, new sexual partners, and anything that disrupts the vaginal microbiome can set it off.
What Treatment Looks Like
BV is treated with prescription antibiotics, either taken orally or applied as a vaginal gel or cream. A typical course lasts five to seven days. Symptoms usually improve within two to three days of starting treatment, but finishing the full course matters because BV has a high recurrence rate. Roughly half of people treated for BV will have it come back within 12 months.
Over-the-counter yeast infection treatments won’t help and can mask the symptoms, making diagnosis harder later. If you’re noticing thin, gray, fishy-smelling discharge for the first time, getting tested is worth it, both to confirm the diagnosis and to rule out trichomoniasis or other infections that can look similar.