Pelvic inflammatory disease does not cause ectopic uterus. Pelvic inflammatory disease refers to inflammatory changes in female reproductive organs, connective tissue around the uterus and pelvic peritoneum, which can trigger symptoms such as lower abdominal pain, chills, high fever and nausea, loss of appetite, etc. It may seriously lead to female infertility and tubal pregnancy. Endometriosis is caused by the growth of endometrium in other parts of the body for some reason. The ectopic endometrium has not only endometrial glands but also endometrial mesenchyme histologically, and there are significant functional changes with estrogen levels in the body, which means that it changes with the menstrual cycle, but only part of it is affected by progesterone, so it produces a small amount of menstruation and causes clinical manifestations.