According to the American Lung Association, COPD is the third leading cause of death in the U.S. Dr. Meyer identifies COPD as one of the most serious and dangerous respiratory illnesses, and COPD is the number one problem seen in most pulmonology offices. “It's a very serious disease. Risks of dying from pneumonia. Pneumonia is an infection of the lungs that can be fatal. ... Infants, adults over 65 years old, people who smoke, or those with an existing lung or chronic health condition are more at risk of pneumonia and life-threatening complications