What is the primary function of expectorants in treating respiratory conditions?

Expectorants play a crucial role in managing respiratory conditions by thinning the secretions in the lungs. This action makes it easier for mucus to be expelled from the respiratory tract during coughing, which is essential for clearing congestion and improving breathing. When the mucus is less viscous, it can be more readily moved by the cilia in the airways, aiding in the clearance of irritants and pathogens.

This function is particularly beneficial in conditions such as bronchitis or sinus infections, where mucus accumulation can obstruct airflow and lead to greater respiratory distress. The ability to effectively clear mucus can also reduce the risk of secondary infections that can arise from stagnant secretions in the lungs.

The other options do not accurately describe the primary function of expectorants. Enhancing mucus production or stimulating breathing rate might be beneficial in certain contexts, but they do not directly address the thinning of mucus, which is the main therapeutic goal of expectorants. Blocking pain receptors in the lungs is not relevant to their function, as expectorants do not have analgesic properties.