The clinical significance of multiple small lymph nodes on abdominal CT is the suspicion of the presence of mesenteric lymphadenitis, ulcerative colitis, and lymphoma. 1. Mesenteric lymphadenitis: This disease is mainly caused by viral infections, mostly Coxsackie B virus, and in a few cases by bacterial, mycoplasma or parasitic infections. Patients will have fever, abdominal pain, vomiting and other symptoms, and the presence of multiple small lymph nodes can be found by CT examination. 2. Ulcerative colitis: the cause of this disease is not yet clear, the typical symptoms include abdominal pain, diarrhea, pus and blood stools, etc. CT examination is one of the key tests to diagnose this disease, which is mostly manifested by the presence of multiple small lymph nodes in the abdomen. 3. Lymphoma: common symptoms include enlarged lymph nodes, chest pain, chest tightness, abdominal pain, etc. CT examination of the patient’s abdomen shows the presence of multiple small lymph nodes. There are many reasons for the patient’s CT abdomen to show multiple small lymph nodes, such as abdominal lymphatic tuberculosis, some connective tissue diseases (e.g. nodular disease, systemic lupus erythematosus, etc.). Further investigations are needed to confirm the diagnosis and treatment accordingly.