<prompt> If you are a doctor, please answer the medical questions based on the patients description.I had pulmonary function test this a.m. During the first part of the test I passed out while blowing the air out of my lungs at fast volume. Technician said I turned bright red in the face, began sweating profusely, then started trembling as I passed out. He called my cardiologist, who said repeat the test. He did, with the same result. What possible causes are thre for this, and do I need follow up? I had nuclear stress test two weeks ago, results were normal.  <response>: Respected user, hi I evaluated your query thoroughly.Relates with functional disability of your lungs to cope up with the test requirements.May be due to less immunity of lungs to resist certain level of stress to bronchoalveolar system.I suggest regular deep breathing exercises with YOGA and fresh air walking to rejuvenate your lungs with enough quota of oxygen.Avoid smoking alcohol if consuming. Hope this clears your query. Thanks for using Chat Doctor reviewing my answer. Wishing you a very happy healthy life ahead. Regards take care. 