Lower abdominal pain in men is commonly caused by the following reasons: First, appendiceal diseases, including chronic appendicitis, acute appendicitis and appendiceal tumor, etc. Patients will experience pain in the right lower abdomen. Second, colorectal diseases, including colitis, colorectal tumors, etc., patients will have vague pain in the lower abdomen, often accompanied by diarrhea and blood in the stool. Third, genitourinary system diseases, such as prostatitis, prostate tumor, cystitis, urinary stones, etc., are often accompanied by abnormal urination, such as hematuria, urinary frequency, urinary urgency and urinary pain. Patients are advised to go to the hospital in a timely manner and need to improve relevant examinations, such as blood routine, urine routine, ultrasound, CT, colonoscopy, etc., to be able to clarify the cause, and then the cause can be addressed and treated accordingly.