What characterizes restrictive lung disease regarding RV and FEV1/FVC ratio?

Restrictive lung disease is characterized by a reduced lung volume, which leads to a decrease in total lung capacity. In this context, the residual volume (RV) is typically decreased because individuals with restrictive lung disease cannot take in a full breath; hence, their lungs cannot hold as much air both at maximal inhalation and exhalation.

The forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) are both reduced in restrictive lung disease, but the ratio of FEV1 to FVC often remains normal or may even increase. This is because both values decline proportionally, so the ratio is maintained or preserved. Therefore, in restrictive lung disease, the FEV1/FVC ratio is typically normal or higher, which helps in differentiating it from obstructive lung disease, where the FEV1 is significantly reduced compared to FVC, leading to a decreased ratio.

Thus, stating that there is reduced RV reflects the nature of lung restriction where the overall volume capacity is diminished, while the normal FEV1/FVC ratio aligns with the characteristic lung mechanics seen in restrictive disease processes.