What is a pneumothorax?

A pneumothorax is defined as a condition where air accumulates in the pleural cavity, the space between the lung and the chest wall. This accumulation of air can create pressure on the lung, preventing it from fully expanding, which can lead to difficulty in breathing and reduced oxygenation of the blood.

In a healthy respiratory system, the pleural cavity contains a small amount of pleural fluid that aids in lubrication during breathing. However, when air enters this space—whether due to trauma, spontaneous rupture of lung tissue, or a medical procedure—it disrupts this balance. Understanding this condition is critical for recognizing its symptoms, which may include sudden chest pain, shortness of breath, and a feeling of tightness in the chest.

The other options define different respiratory issues. The presence of fluid in the lungs refers to conditions like pulmonary edema, a type of lung infection points to pneumonia, and a blockage in the airway relates to conditions such as asthma or choking. Each of these plays a distinct role in respiratory health, but they are not synonymous with pneumothorax.