More than 12 million Americans have been diagnosed with chronic obstructive pulmonary disease, or COPD, and another 12 million have it but don't know it. It's now the third leading cause of death in America, yet many people are unaware of COPD and its devastating effect on the lungs. After NASCAR and IndyCar driver Danica Patrick's grandmother died of COPD at age 61, Patrick pledged to help raise awareness about the disease. Patrick's grandmother was a smoker, and smoking is the leading cause of COPD, though not the only one. Patrick has pledged to lead a healthy lifestyle and never smoke to reduce her risk of COPD. See what other celebrities have to say about the condition and what their famous COPD stories can mean for other patients.