Dear Dr. Donohue - My mother is in her early 70s. She has been diagnosed with chronic obstructive pulmonary disease, COPD. She had a bronchoscopic exam to remove a mucus plug. She was a very heavy smoker. She still smokes. She thinks her kids don't know, but we have seen the evidence. She is on oxygen. Her doctor thinks she has quit. What does this do to her life expectancy? How long can she live this way? - J.S.

Answer - Chronic obstructive pulmonary disease, COPD, is two illnesses: emphysema and chronic bronchitis. Emphysema is a harmful stretching and destruction of the millions of air sacs found in the lungs. Through those delicate structures, oxygen reaches the blood. When they are damaged, a person cannot get enough oxygen and becomes breathless on even slight exertion. Chronic bronchitis is inflammation of the air passageways, the bronchi. They fill with thick, pus-filled globs of phlegm. Air cannot pass through them. A cough that produces of sticky, tenacious sputum is its chief sign.

Cigarette smoking is the major cause of COPD, but not the only one.

It's hard to watch people ruin their bodies and hasten death. Tell her that the most important treatment for COPD is total abstinence from smoking. Abstinence allows lungs to recover from the damage done from inhaling cigarette smoke. It doesn't achieve a complete reversal overnight. It does prolong life.