Blood blisters on a woman’s lower vagina may be caused by pemphigus, vulvovaginitis, genital herpes and other factors. 1. pemphigus: the disease may be related to autoimmunity, value-added pemphigus may appear in the vulvar area, the vulvar skin will initially appear blood-colored blister-like lesions, and granulomatous hyperplasia will appear after the rupture. 2. Vulvovaginitis: this disease may be related to infection, physical and chemical stimulation and other factors, non-specific vulvovaginitis will lead to the appearance of blood blisters on the vulva, may also be accompanied by vulvar skin itching, pain and other symptoms. 3. Genital herpes: this disease is generally caused by herpes simplex virus infection, the patient’s genitals may appear around the blood blisters, blisters may break, scabs, some patients will be accompanied by symptoms of lymph node swelling and pain. Women who have blood blisters on the vulva should go to the hospital in time for treatment.