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 ( Emphysema vs. Chronic Bronchitis: What's the Difference? Emphysema vs. Chronic Bronchitis: Key Differences (2026) Smoking cigarettes has long been proven to cause severe lung damage, including chronic obstructive pulmonary disease (COPD), emphysema, and lung cancer. Over time, cigarette smoke destroys lung tissue, fills airways with tar, Chronic Obstructive Pulmonary Disease (COPD) Causes, Symptoms & Treatment