What happens to the lungs during pleurisy?

During pleurisy, the pleural membranes that line the lungs and the inner chest wall become inflamed and irritated. This inflammation leads to the accumulation of fluid in the pleural space, which is the area between the lungs and the chest wall. This fluid can cause the lungs to become compressed, restricting their ability to expand and contract. As a result, breathing can become difficult and painful.

The inflammation associated with pleurisy can also cause a thickening and scarring of the pleural membranes. This can lead to long-term problems with lung function, such as reduced lung capacity and shortness of breath.

In severe cases, pleurisy can lead to a condition called empyema, in which the pleural fluid becomes infected. This can be a serious condition and can require hospitalization and treatment with antibiotics.