2) Breathing changes
As the lungs are associated with breathing, any pathology occurring in the lungs may cause certain changes in the breathing pattern. If you are exerting yourself or exercising, you will naturally become short of breath. However, a positive sign of lung cancer could be shortness of breath or gasping breathing pattern (one that you experience after running or heavy exercise), especially after performing activities you normally perform every day such as doing one flight of stairs or just walking from one room to another. This indicates that something is wrong with your functional part of the lungs.
Of note, the change in the breathing pattern could be due to multiple other reasons such as severe anemia, pregnancy, ischemic heart diseases, or non-cancerous causes of the lungs, e.g., asthma, pulmonary embolism, chronic bronchitis, bronchiolitis, pulmonary tuberculosis, infections of the respiratory tract, or inhalation of foreign bodies into the lungs. Therefore, it is important to have a proper checkup from pulmonologists or cardiologist to investigate and exclude the non-cancerous causes.
