Abdominal swelling on the left side has many potential causes, one being acute pancreatitis, according to Healthline. The National Institutes of Health cites diverticulitis as another other possible cause.
Acute pancreatitis is inflammation of the pancreas, an organ found in the upper left quadrant of the abdomen, states Healthline. Acute pancreatitis can be caused by gallstone blockage of the pancreatic duct, viral infections, an autoimmune attack on the pancreas, excessive blood triglyceride levels, certain types of medication, or physical damage to the organ. Pancreatitis is treatable with medication to eliminate the inflammation. In severe cases, surgery may be needed to drain fluids or to remove a blockage or damaged tissue.
Diverticulitis is inflammation or bacterial infection of tiny pouches in the colon wall called diverticula, reports WebMD. The most common symptom is pain in the lower left portion of the abdomen. Diverticulitis is treatable with antibiotics. Diverticula formation is poorly understood, but a low-fiber diet may be a possible cause.