A constant foul odor in the lower part of a woman is not necessarily caused by syphilis, but may also be caused by gynecological diseases such as cervicitis, vaginitis, malignant tumors of the cervix, endometrial cancer, etc. Therefore, it needs to be clarified in combination with other symptoms and relevant auxiliary examinations. If a woman has a foul odor in the lower body, accompanied by dark red hard lumps, shallow ulcers with cartilage-like hardness in the external genital area, enlarged surrounding lymph nodes, mucosal spots and flat warts in the mucous membrane, syphilis is considered a high possibility and can be confirmed by tests such as syphilis serology test. If the vaginal discharge and odor are abnormal, it may be caused by lack of personal hygiene or vaginitis or cervicitis. In order to prevent syphilis, cervicitis and vaginitis, women should pay attention to personal hygiene, change underwear regularly and avoid unclean sex.