Pain in the lower and middle abdomen may be associated with intestinal disorders (enteritis, tumors), urologic disorders (ureteral stones, bladder stones, cystitis, prostatitis), and reproductive disorders. 1. Bowel diseases (1) Enteritis is an inflammatory disease that occurs in the intestines and is related to cold in the abdomen in addition to unclean diet. The site of pain usually occurs in the umbilicus, but can also be in any part of the whole abdomen. (2) The pain caused by intestinal tumor is related to the compression caused by the tumor on the surrounding tissues, and the abdominal mass can usually be touched. 2. Urological diseases (1) The pain in the middle and lower abdomen caused by ureteral stones and bladder stones is related to the irritation caused by the stones on the ureteral wall and bladder wall, and in addition to the pain, it may also be accompanied by hematuria as well as symptoms of urethral irritation such as urinary urgency and urinary pain. (2) Cystitis and prostatitis in men can also cause pain in the lower and middle abdomen, accompanied by urinary tract irritation such as urinary urgency, urinary frequency or urinary pain. 3. Reproductive system diseases: Infectious diseases such as pelvic inflammatory disease, adnexitis and endometritis in women can also cause pain in the lower and middle abdomen, which is usually accompanied by abnormal changes in the leukorrhea. Due to the individual differences in clinical manifestations, it is necessary to consult a doctor for a clear diagnosis and targeted treatment.