Bacterial vaginosis is the most common infection of the vagina, along with fungal and trichomoniasis. Bacterial vaginosis is considered a moderate bacterial infection of the vagina. It is believed that its cause is a violation of the natural balance between the microorganisms that make up the vaginal microflora. The composition of the vaginal microflora includes both useful “good” bacteria and conditionally pathogenic ones. In a healthy organism, they mutually influence each other, which prevents the growth of both, thus maintaining a favorable healthy environment in the vagina. However, when the immune system declines, the balance can easily be disturbed, whereby the amount of conditionally pathogenic microorganisms increases at the expense of beneficial ones. This can lead to infection and illness. It is possible for bacterial vaginosis to appear and disappear in a few days, without the affected woman even being aware of her condition. In other cases, however, it can lead to complaints. A higher frequency and risk of bacterial vaginosis is observed when changing sexual partners or having sex with more sexual partners, doing vaginal douching, factors such as prolonged exposure to the sun, smoking, etc. It should be clear, however, that although it occurs in women of sexually active age, the cause of bacterial vaginosis may not lie in the partner. How can such claims be explained? On the skin, including the mucous membranes of the genital organs, we normally carry a set of microorganisms that we acquired at birth. Some of these microorganisms have useful functions for our body – similar to lactobacilli, which are also found in the vagina and secrete lactic acid, and thanks to it, the natural acidic environment there is normalized, which in turn protects against infections. However, the set of microorganisms differs from person to person (it is relatively similar among people who maintain close contacts in the same family). During sexual contact with a new partner, without precautions, a type of exchange of microorganisms occurs. Due to the specificity of the female genital organs, this exchange is “more fatal” for her – new microorganisms can upset the balance of the vaginal microflora, especially if the woman is susceptible to infections and has labile immunity. NEWS_MORE_BOX There is a similar problem with a way of life with more than one partner, in which conditions are created for the continuous disturbance of the balance of the vaginal microflora, without giving it time to restore it or to build another one with the inclusion of new microorganisms in its composition. The problem is related to a weakening of local immunity and a tendency to easy infection. Prolonged exposure to the sun leads to a decline in the immune system in general, and in more sensitive organisms this can reflect “on the weak spot”. The combination of exposure to the sun, contact with polluted water (sea,in a pool) and other environments contribute to increasing the risk of developing bacterial vaginosis. Using a vaginal douche for a woman’s discomfort or to maintain vaginal cleanliness was a common practice years ago. In the last decade, however, the method has been increasingly rejected by specialists. First, because in the presence of even a small number of pathogenic microorganisms, they could be transferred through the shower and reach the uterus, where they can cause serious damage. Second, vaginal douching disrupts the natural mechanisms for maintaining a healthy vaginal environment. Regarding smoking, it is more about citing results from medical studies. In the sequel: how bacterial vaginosis is treated