Bacterial vaginosis (BV) originates from an imbalance of the naturally occurring bacteria in the vagina. Normally, a healthy vagina contains a predominance of "good" bacteria, mainly Lactobacillus species, which help maintain an acidic environment that prevents overgrowth of harmful bacteria. BV occurs when this balance is disrupted, leading to an overgrowth of other bacteria such as Gardnerella vaginalis and various anaerobic bacteria, which replace the beneficial lactobacilli

. The exact cause of this bacterial imbalance is not fully understood, but several factors are known to increase the risk of developing BV. These include douching, having new or multiple sexual partners, not using condoms, antibiotic use, and the use of intrauterine devices (IUDs)

. Although BV is associated with sexual activity, it is not classified as a sexually transmitted infection, and it can also occur in sexually inactive individuals

. In summary, BV comes from a disruption in the vaginal microbiota where harmful bacteria overgrow and beneficial bacteria decline, often triggered by behaviors or conditions that alter the vaginal environment