What condition can cause a decrease in lung compliance?

A decrease in lung compliance refers to the reduced ability of the lungs to expand during inhalation. This can be caused by several conditions, but pneumonia is a particularly relevant example.

In pneumonia, the lung tissue becomes inflamed and fills with fluid or pus, which can make the alveoli less functional and more difficult for air to fill. The presence of infection and inflammatory substances leads to consolidation of lung tissue, which ultimately stiffens the lungs, causing decreased compliance. When compliance is low, more pressure is required to achieve the same volume of air inhaled, making breathing more labored.

While asthma exacerbations can also affect lung function, they typically cause airway obstruction rather than a direct reduction in lung compliance. Chronic obstructive pulmonary disease (COPD) is associated with increased compliance due to loss of elastic recoil but can exhibit other functional impairments. Inflammation of the pleura, known as pleuritis, can result in pain during breathing but does not necessarily decrease lung compliance itself; it affects the pleural space rather than the lung tissue directly.

Thus, pneumonia distinctly impacts lung compliance through the pathological changes it induces in lung tissue.