Common causes of pain on the left side of the body include infection and injury to muscles, nerves, or internal organs, such as the heart, spleen, left lung or kidney, pancreas, and more.

Pain in the LUQ may be due to digestive issues or conditions related to organs in that abdominal region, such as the spleen .

The pancreas is an organ behind the stomach and near the spleen. It performs both exocrine and endocrine functions. The exocrine cells release digestive enzymes to assist with breaking down food.