What is the normal pH of vagina in adult woman?

The normal vaginal pH is between 3.8 and 4.5. A pH higher than 4.5 indicates either bacterial vaginosis or trichomoniasis. Lactic acid produced by L.acidophilus suppresses the growth of gram positive and gram negative facultative and obligate anaerobes and maintains a normal pH and inhibits the adhesion of bacteria to the vaginal epithelial cells. Vagina: It is a strong, hollow, fibromuscular canal approximately 7-9 cm long that extends from the uterus to the vestibule of the external genitalia. The vaginal wall is composed of a mucosal layer and a muscular layer. The mucosa of the vagina is lined throughout by nonkeratinized squamous epithelium. The chief blood supply to the vagina is through the vaginal branch of the uterine aery. Ref: Clinical Pathology By James Caon page 255. Management of Common Problems in Obstetrics and Gynecology edited by T. Murphy Goodwin oage 225.