BV discharge is a thin, off-white to grayish vaginal discharge with a noticeable “fishy” smell. It’s the hallmark sign of bacterial vaginosis, the most common vaginal infection in women of reproductive age. The discharge happens when harmful bacteria outgrow the protective bacteria that normally keep the vagina’s environment balanced.
What BV Discharge Looks and Smells Like
The discharge from bacterial vaginosis has a distinctive appearance that sets it apart from normal vaginal discharge. It’s thin and homogeneous, with a milk-like consistency that smoothly coats the vaginal walls rather than clumping or forming chunks. The color ranges from off-white to gray, and in some cases it can have a greenish tint.
The most recognizable feature is the smell. BV produces a strong fishy odor that often becomes more intense after sex. This smell comes from chemical compounds released by the overgrown bacteria. Some people notice the odor is also stronger during their period. Not everyone with BV has obvious symptoms, but when the smell is present, it’s usually the first thing that prompts someone to seek answers.
BV Discharge vs. Yeast Infection Discharge
These two infections are easy to confuse, but the discharge looks and feels quite different. BV discharge is thin, grayish, and has that characteristic fishy smell. A yeast infection produces thick, white, clumpy discharge that often looks like cottage cheese, and it typically has no significant odor.
The other major difference is itching. Yeast infections cause intense vaginal itching and irritation. BV rarely causes itching at all. So if your main symptom is a foul-smelling, thin discharge without much itch, BV is the more likely cause. If you’re dealing with thick, odorless discharge and significant itching, a yeast infection is more probable. This distinction matters because the two conditions require completely different treatments.
What Causes It
Your vagina naturally contains a balance of bacteria, with protective species (lactobacilli) keeping the environment slightly acidic. This acidity prevents harmful bacteria from gaining a foothold. BV develops when that balance shifts: the protective bacteria decline and other bacteria multiply rapidly, raising the vaginal pH above 4.5. A healthy vaginal pH sits below that threshold.
Several things can trigger this shift. Douching is one of the most common disruptors, because it strips away the protective bacteria and changes the vagina’s chemistry. Having new or multiple sexual partners and not using condoms also increases risk. Sex can introduce new bacteria or alter the vaginal environment enough to tip the balance. BV is not considered a sexually transmitted infection, but sexual activity is clearly linked to its development.
How BV Is Diagnosed
A healthcare provider can usually diagnose BV during a routine exam. The clinical criteria require at least three of four specific findings: the characteristic thin, homogeneous discharge; a vaginal pH above 4.5; a fishy odor when a chemical solution is applied to a sample of the discharge; and the presence of “clue cells” under a microscope, which are vaginal cells covered in a visible coating of bacteria. In most cases, the appearance and smell of the discharge alone are strong indicators, but testing confirms it.
Treatment and Recurrence
BV is treated with antibiotics, which are available as oral pills or vaginal gels or creams. Treatment typically clears the discharge and odor within a few days. The problem is that BV has one of the highest recurrence rates of any common infection. Between 50 and 80 percent of women experience BV again within a year of completing antibiotic treatment. This high recurrence rate is frustrating, and it happens because antibiotics kill the overgrown bacteria but don’t always fully restore the protective bacterial community.
To reduce your chances of recurrence, avoiding douching is one of the most effective steps you can take. Using condoms and limiting disruptions to vaginal chemistry can also help. Some people deal with repeated episodes for months or years, and in those cases, longer or repeated courses of treatment may be necessary.
BV During Pregnancy
BV carries additional risks during pregnancy. People with BV while pregnant may be more likely to deliver before 37 weeks, though researchers have not definitively established that BV directly causes preterm delivery. Preterm birth is linked to serious complications for newborns, including breathing problems and bleeding in the brain. If you’re pregnant and notice thin, fishy-smelling discharge, getting tested early gives you the best chance of treating it before complications develop.