Why do smokers take longer to recover from respiratory infections?

Smokers take longer to recover from respiratory infections like the common cold, influenza, and pneumonia because cigarette smoke causes significant, long-term damage to the respiratory system.1

The habit leads to an increase in the size and number of mucous glands in the airways, resulting in chronic bronchitis and the persistent production of sputum. Furthermore, smoking causes inflammation and structural changes in the smaller bronchioles, which can lead to chronic obstructive pulmonary disease (COPD). These underlying conditions compromise the lung's ventilatory ability and overall health, making it more difficult for the body to clear infections and recover efficiently compared to nonsmokers.21