The left side of the anterior waist and abdomen than the right side of the anterior waist and abdomen may be uneven accumulation of fat, intestinal diseases, left abdominal organs tumors, etc., should be timely consultation to identify the cause of the disease. 1. Uneven fat accumulation: If you lie down immediately after eating, and have been lying on the left side, in the long run, it will cause the fat accumulation on the left side of the abdomen to be more serious than that on the right side, which will result in the left anterior lumbar abdominal area being bigger than the right anterior lumbar abdominal area. 2. Intestinal diseases: such as intestinal distension, especially in patients with long-term constipation, the left half of the colon may store more stool or even gas, which makes the left anterior lumbar abdomen feel larger than the right anterior lumbar abdomen. 3. Tumor of left side abdominal organs: such as left colon cancer, or mesenteric mesothelioma, the tumor may be located in the left side of the abdomen, and the relevant performance may appear. However, other factors can not be ruled out. It is recommended to consult the doctor in time and give targeted treatment after the doctor clarifies the cause of the disease.