What Could Cause Swelling in the Left Upper Abdomen?

Swelling in the left upper part of your abdomen can be caused by a few different conditions. One possibility is that an inflammatory condition is affecting the area. Another possible cause is an enlarged spleen. For example, patients with mono can present with swelling in the left upper abdomen due to an enlarged spleen.
Another potential explanation is edema, or fluid accumulation, which can happen due to various reasons such as problems with liver or kidney function or other systemic issues that disrupt your body’s fluid balance. Swelling might also come from localized infections or inflammations affecting the stomach, spleen, or colon, or even from a mass or growth in that region. Because these causes range from relatively benign to more serious conditions, it’s important to have persistent or concerning swelling evaluated by a healthcare provider. They may perform a physical examination and order imaging studies, like an ultrasound or CT scan, to pinpoint the exact cause and determine the most appropriate treatment for your condition.