The vaginal microbiome in healthy women of reproductive age includes numerous aerobic, facultative anaerobic and obligate anaerobic microorganisms. Of these, the number of anaerobes populations is the highest. These bacteria are in symbiosis with the human body, but in some cases an imbalance may occur in the vaginal flora. Some of these microorganisms produce lactic acid or hydrogen peroxide, which have a protective effect and prevent the entry of disease-causing bacteria. A secretory leukocyte protease inhibitor is also released into the vagina to protect against multiple toxic substances. It is a protein that has a protective effect on tissues against toxic products that are released during inflammatory processes and infections. Some of the bacteria in the vaginal flora can reach the upper parts of the reproductive system without causing infection. The average vaginal pH is between 4 and 4.5. Lactobacillus bacteria have been found to contribute to the release of lactic acid, which acidifies the environment in the vagina. Glycogen is a natural constituent of the vaginal mucosa and provides nutrients for the bacteria in the vagina, but it is also metabolized to glycogen. Its content falls naturally when entering menopause, which leads to a reduced availability of building blocks for the synthesis of acids. This leads to an increase in vaginal pH. The change in these parameters leads to preferential distribution of certain types of bacteria. An imbalance in the vaginal flora can lead to infections. In women of childbearing age, menstruation leads to transient changes in the vaginal microbiome. Menstrual blood can also in some cases be an effective nutrient medium for the development of some pathogenic microorganisms. Often, the symptoms of vaginal infections appear immediately after the start or stop of menstruation. Bacterial vaginosis is a frequent consequence of an imbalance of the microbiome in the vagina. The causative agents of this disease are diverse: Gardnerella vaginalis, Ureaplasma urealyticum, Mobiluncus species, Mycoplasma hominis and Prevotella species. Bacterial vaginosis can also be associated with a decrease in the number of populations or a complete absence of Lactobacillus species. A key risk for developing bacterial vaginosis is frequent sexual contact with different partners. Other risk factors are: Oral intercourse; Intimate showers; Smoking; Intercourse during menstruation; Use of intrauterine contraceptives; Early age of initiation of sexual life. This disease is the leading cause of the presence of pathological secretion from the vagina. Symptoms can be different, depending on the cause. The complications of the disease are significant. They include: Vaginitis – inflammation of the vagina; Endometritis – inflammation of the endometrium – the inner layer,covering the uterine cavity; Postpartum endometritis; Pelvic inflammatory disease; Acute infections of the organs in the small pelvis; Infections during pregnancy are associated with an increased risk of preterm birth. The treatment of bacterial vaginosis is based on the use of antibiotics, which ensure the restoration of balance in the vaginal microbiome. Among the most used are penicillins. They are the agent of first choice and provide effective tissue penetration. Genital ulcers – ulcerations are due to loss of epidermal covering and invasion of the underlying dermis. Genital herpes is a leading cause of vaginal ulceration and is due to a chronic viral infection. There are two types of herpes viruses, of which Herpes simplex virus 2 – HSV-2 is the cause of genital involvement. Most cases are asymptomatic. Since the virus affects the epidermis, the most common manifestations are redness – erythema and the formation of vesicles. Destruction of the cells in the affected area leads to ulceration of the tissue. The three stages of development of the lesions are: formation of vesicles with or without subsequent formation of pustules, ulceration and finally crusting of the lesions. A common symptom is a burning sensation and severe pain. Due to ulceration, disturbances and discomfort during urination and local edema may be observed. Herpes infection can affect the vagina, cervix, bladder, anus and the rectum. References: Williams Gynecology, 4th Edition, McGraw Hill Education, 2020