Enlargement of the uterus refers to an increase in the volume of the uterine cavity or a significant increase in the size of the uterus due to organic disease. 1. Increase in uterine cavity volume: After pregnancy, the fetus grows and develops in the uterine cavity, and there is amniotic fluid and fetal appendages such as placenta in the uterine cavity, which may cause an increase in uterine cavity volume. 2. Organic diseases: some female patients have uterine enlargement, which may be caused by various organic diseases such as adenomyosis, fibroids, endometritis, myositis, endometrial cancer, uterine sarcoma and other uterine volume increase. Targeted treatment is needed depending on the disease. In the event of uterine enlargement, routine gynecological examination and pelvic ultrasound examination under the guidance of obstetricians and gynecologists are needed to clarify the diagnosis and standardize the treatment.