1. Shortness of breath
The lungs are essential for gas exchange. This is where oxygen enters the blood, and we take out carbon dioxide. For this exchange to occur, we need a constant flow of air coming in and out. The problem here is that tumors in the lungs create an obstacle to gas exchange. This obstacle can be very small and difficult to perceive. In advanced cancer, the tumor grows very large, and this symptom is very severe. Additionally, cancer prompts an inflammatory response, affects respiratory muscles, and creates the sensation of running out of breath.