I had been diagnosed as having COPD by a Pulmonary Specialist (MD) and had been treated for such for about 10-years. I typically got bronchitis about 10 times per year; each time I got a cold and sore throat. Had to use inhaler for all moderate exercise.
Was visiting my DO for a pulled muscle and started coughing. When he asked what was going on, I replied that I had COPD. He did some homeopathic-type tests and announced that I did not have COPD - I was allergic to dairy products. Dairy products were producing too much mucus in my lungs and that's why I had troubles breathing and getting bronchitis. He suggested I eliminate diary products from my diet.
I was skeptical, but tried it anyways. I was so surprised! I have been off of all medications (inhaled steriodsdaily and inhaler before exercising) for 4-years. If I fall into temptation and eat some ice cream, I feel the affects on my lungs within the hour.
So, if you have COPD, try cutting out diary products. I wish you excellent results and health.