I've been noticing this weird pain in the upper left side of my chest, especially when I yawn. It's not constant, but more annoying in the mornings. Should I be worried about this? What could be causing it? Any advice would be appreciated.

The intermittent chest pain in your left upper chest, particularly when yawning, could be related to musculoskeletal issues, such as costochondritis (inflammation of the cartilage connecting ribs to the breastbone) or intercostal muscle strain; however, to rule out cardiac or pulmonary causes, consult a cardiologist or a primary care physician for a thorough evaluation, including a physical exam, electrocardiogram (ECG), and possibly a chest X-ray or stress test.