Vaginal bleeding in 80 year olds may be clinically caused by the following reasons: First, vaginal inflammation in old age. After menopause, the decrease of estrogen and local resistance of the vagina may lead to local inflammatory reaction, causing local mucosal congestion and bleeding. Secondly, it may be caused by cervical cancer. When there is cancer in the cervix, it will manifest clinically as vaginal bleeding and a great foul smell, which is the clinical manifestation of cervical cancer. Thirdly, it may be caused by endometrial cancer. When there is cancer in the endometrium, it will manifest as vaginal bleeding, and in the advanced stage of cancer, the necrosis and infection of cancerous tissues will lead to foul-smelling discharge, so it is recommended to actively go to the hospital for examination, diagnostic scraping and cervical cancer screening if necessary, and timely treatment after diagnosis.