Smoking can cause lung disease by damaging your airways and the small air sacs (alveoli) found in your lungs. Lung diseases caused by smoking include COPD, which includes emphysema and chronic bronchitis. Cigarette smoking causes most cases of lung cancer.
A study in the January 24 issue of The BMJ found that smoking even one cigarette a day carries significant health consequences, namely a higher risk of heart attack and stroke.
