Book excerpt: Most people don't think about breathing; it is an automatic, unconscious act. However, the majority of those with asthma (26 million Americans); chronic obstructive pulmonary disease, or COPD (24 million Americans); or interstitial lung disease (1-2 million Americans) are aware of their shortness of breath because it interferes with work or other daily activities. As a result, these individuals seek medical attention for diagnosis and treatment. Breathe Easy, written by a pulmonologist, explains what constitutes normal breathing, what causes someone to feel short of breath, and what can be done to improve one's breathing. In chapters on asthma, COPD, and interstitial lung disease, Dr. Donald A. Mahler addresses the origins and treatments of these conditions, and offers advice for both standard and alternative therapies to breathe easy. Other chapters describe how we breathe, how to understand respiratory difficulties like chronic shortness of breath, the correct use of inhalers, the effects of aging on the brain and body, and the benefits of exercise. His final chapter provides valuable advice about traveling with oxygen. Illustrated with over fifty enlightening medical graphics, Breathe Easy offers a complete and compact guide for the millions of Americans who are limited by their breathing.