Why when people smokes often have trouble breathing?

People who smoke often experience trouble breathing due to the harmful chemicals in tobacco smoke, which can damage the lungs and airways. Smoking leads to inflammation, reduced lung function, and the development of conditions such as chronic obstructive pulmonary disease (COPD) and emphysema. Additionally, the mucus production increases, and the cilia that help clear airways become impaired, further obstructing airflow and making breathing more difficult.