The most common causes of vague pain in the upper left abdomen in men are the following: 1. Spleen diseases, such as spleen abscess, spleen tumor, enlarged spleen due to cirrhosis, and enlarged spleen due to hematological diseases, such as leukemia, can cause vague pain in the upper left abdomen, and patients are advised to improve routine blood tests, liver function tests, and abdominal CT examinations to assist in the diagnosis. 2. It is recommended to improve amylase examination and abdominal CT examination to assist in the diagnosis. 3.Colon tumor, mainly referring to colon cancer, generally manifests as vague pain in the upper left abdomen, blood in the stool, diarrhea and a feeling of urgency. 4.If patients have inflammation of the colon, they will have vague pain in the upper left abdomen. It is recommended to improve the routine stool examination and colonoscopy.