Trichomonas vulvitis is often secondary to Trichomonas vaginitis. In women, Trichomonas vaginalis mostly parasitizes the vagina, urethra, Bartholin's glands and bladder. Involvement of the Bartholin's glands is rare. Trichomonas vaginalis is a flagellate that is much larger than polymorphonuclear leukocytes, pear-shaped, with four flagella on the top and a protruding axial column at the tail. It can parasitize in the human body without causing clinical symptoms. Certain bacteria can induce Trichomonas to become active and produce symptoms, but antibodies in the body can be transmitted directly or indirectly, mainly through baths, bathing utensils, swimming pools, or incompletely disinfected medical equipment. Direct transmission can be through sexual intercourse, from the male urinary system, and the patient's urine and feces may also be the source.