How are the symptoms of trichomonal vaginitis caused?

The symptoms of trichomonal vaginitis are primarily caused by infection with Trichomonas vaginalis, a pathogen transmitted through sexual contact and one of the more common sexually transmitted infections. After infection, changes occur in the vaginal environment, allowing the trichomonads to multiply, consume glycogen from vaginal epithelial cells, and disrupt the vagina's self-cleaning capacity. This leads to an elevated pH level and triggers a series of inflammatory responses. These manifest as increased vaginal discharge that becomes abnormal in color—changing from normal white and translucent to grayish-yellow or yellow-green—and develops a thin, watery or frothy consistency. Patients may also experience itching and burning sensations in the external genitalia, pain during intercourse, as well as urinary symptoms such as frequent urination, urgency, and dysuria. The emergence of these discomforts is a direct result of Trichomonas vaginalis infection and its disruption of the vaginal microenvironment.