Due to the structure of the human body, there are not many organs on the left side of the abdomen, so if the left side of the abdomen is painful, the following problems are generally considered: first, colitis, especially sigmoid colon, which is mainly characterized by left lower abdominal pain, but often accompanied by changes in the number of bowel movements or stool properties. The second, ureteral stones, but the pain will be more intense, and often accompanied by lumbar spine, paraspinal pain, or lumbar aches and pains. The third is prostatitis, which is characterized by a feeling of heavy pressure in the perineum or suprapubic area, and the symptoms are aggravated when sitting for a long time or defecating. Fourth, varicocele is also a common cause of lower left abdominal pain. The pain in the left lower abdomen in men is caused by varicocele, which is more obvious when sitting, and the pain will radiate to the left perineum, and sometimes accompanied by hidden pain in the testicles. These are a few of the common causes of lower left abdominal pain.