Bleeding again after one and a half years of menopause may be related to vaginitis, un-removed intrauterine device, endometrial cancer and so on. 1. Vaginitis: the level of estrogen in the body decreases after menopause. Due to the atrophy of vaginal mucosa, local resistance is reduced. Bacteria, chlamydia and other pathogens may cause vaginal inflammation. Inflammation constantly stimulates blood vessels, leading to the formation of ulcers bleeding in some blood vessels. 2. Intrauterine device is not removed: after menopause, ovarian function declines, sex hormone secretion decreases, and the uterus shrinks. However, the size of IUD remains unchanged, so the IUD will be embedded in the muscle layer of the uterus, which will easily cause bleeding. 3. Endometrial cancer: it may be related to gene mutation or due to lack of progesterone to fight against it, the endometrium is in a state of excessive proliferation for a long time, which triggers endometrial cancer. Bleeding may be due to the continuous proliferation of the endometrium, which may break down. In addition to the above, bleeding after one and a half years of menopause can also be caused by other reasons. It is recommended to consult a doctor for further examination to identify the cause and to carry out targeted treatment or therapy with the help of the doctor.