Smoking poses severe dangers to lung health, including: 1. Lung Cancer Smoking is the leading cause of lung cancer, increasing the risk of developing this deadly disease. 2. Chronic Obstructive Pulmonary Disease ( Childhood Cigarette Smoking and Risk of COPD Journal of the COPD Foundation Chronic Obstructive Pulmonary Disease (COPD) Temple Health E cigarette use tied to increased COPD, asthma risk MDedge Disease Lungs Chronic Bronchitis The Common Vein