What is the main characteristic of restrictive lung disorders?

Restrictive lung disorders are primarily characterized by a reduced lung volume. This reduction means that the lungs are unable to expand fully during inhalation, leading to a decrease in the total amount of air that can be inhaled. This can occur due to various factors such as stiffness of the lung tissue, abnormalities in the pleura, or conditions affecting the chest wall that limit its ability to expand.

In restrictive lung disorders, although airflow may still be relatively unobstructed compared to obstructive disorders, the critical issue lies in the decrease in compliance or the ability of the lungs to expand, which ultimately affects the volume of air exchanged during respiration. This characteristic is fundamental in defining restrictive lung conditions and is key to distinguishing these disorders from obstructive types, where the primary issue involves difficulty in airflow due to narrowed or blocked airways.

The other options focus on aspects such as airway obstruction, inflammation, and infections, which are not defining features of restrictive lung disorders. Instead, they point to different mechanisms or causes found in other respiratory conditions.