What is pneumothorax (PTX)?

Pneumothorax, or PTX, refers specifically to the presence of air in the pleural space, which is the thin fluid-filled space between the layers of tissue lining the lungs and chest cavity. This condition can arise from various causes, including trauma, lung disease, or rupture of a bleb, leading to a collapse of the lung on the affected side. The accumulation of air disrupts the normal negative pressure that keeps the lungs inflated, which can result in respiratory distress and requires medical attention to evaluate and, if necessary, remove the trapped air to allow proper lung expansion.

Other options describe different medical conditions. For instance, an allergic reaction in the lungs pertains to responses to allergens that can cause symptoms like wheezing or shortness of breath, which does not align with the definition of pneumothorax. Fluid accumulation around the heart refers to a condition known as pericardial effusion, and an infection in the lung tissues typically describes pneumonia. Each of these conditions has distinct characteristics, causes, and treatments, differentiating them from pneumothorax.