Multiple enlarged retroperitoneal lymph nodes refer to the enlargement of all lymph nodes in this area of the retroperitoneal space. This area covers a wide range of organs and connective tissues, including the duodenum, ureter, adrenal glands, kidneys, sympathetic nerves, abdominal aorta, spinal nerves, and inferior vena cava, which are rich in lymph nodes called retroperitoneal lymph nodes. Many diseases may cause the lymph nodes in this area to become enlarged, such as lymphatic tuberculosis, chronic lymph node inflammation and malignant tumors, etc. If you find enlarged lymph nodes, you should pay attention to them and promptly go to the hospital for CT or imaging examinations to clarify the cause and then treat them accordingly.