COPD is otherwise known as chronic obstructive pulmonary disease. Millions of people suffer from COPD every year, and according to the American Lung Association, it is the third highest cause of death due to a disease in the US. In COPD, the air passages in the lungs get inflamed, which leads to less air flowing through. When the airways in the lungs get damaged by inflammation, this makes it more difficult for air to get in and out. This can lead to trapping of air in the lungs and less fresh air can make it into the lungs, which makes it difficult to breathe.