Hi, The lungs structure is grossly changed from the normal tissue to fibrosis and areas with air (emphysema). This can happen in some patients without a clear reason but in many patients it is due to irritants taken with air like smoking or if you have worked in places with dust (also called pneumoconiosis). You will need to be closely monitored by your doctor as this can develop into low lung function due to chronic obstructive pulmonary disease (COPD) with shortness of breath that may progress. If you are smoking it is absolutely necessary to quit to prevent further development and if you work with dust this is something that needs attention as well. Hope I have answered your query. Let me know if I can assist you further.