Donald A. Mahler, MD, is emeritus professor of medicine at Geisel School of Medicine at Dartmouth, and staff pulmonologist and director of respiratory services at Valley Regional Hospital in Claremont, New Hampshire. He is the author of COPD: Answers to Your Questions.
Most people don’t think about breathing; it is an automatic, unconscious act. However, the majority of those with asthma (26 million Americans); chronic...