<s>[INST] Have been diagnosed with mildly inflated lungs some 4 years agony.I can run 5-9k withou a problem ,, latest lung test gave a reading of 2.9 , I am 51 years of age .Why am I recently short of breath( walked through a construction site full of dust last week). [/INST] Thanks for your question on Chat Doctor. I can understand your concern. In my opinion, you are mostly having bronchitis due to exposure of dust. Dust is irritant in nature and can cause inflammatory reaction in airways. So patient feels breathlessness. Same thing is happening in your case. So better to consult pulmonologist and get done clinical examination of respiratory system and PFT (Pulmonary Function Test) for the diagnosis of bronchitis. You may need inhaled bronchodilators and inhaled corticosteroid. Don't worry, you will be alright with this treatment. Avoid exposure to dust, smoke and pollution. Hope I have solved your query. Wish you good health. Thanks. </s>