What term describes the presence of air in the pleural cavity?

Pneumothorax refers specifically to the presence of air within the pleural cavity, the space between the pleurae that covers the lungs and lines the thoracic cavity. This condition can occur due to trauma, disease, or spontaneously, leading to a collapse of the lung on the affected side. The buildup of air in this cavity disrupts the negative pressure that is essential for lung expansion during inhalation, which can cause difficulty in breathing and other respiratory symptoms.

In contrast, atelectasis is the collapse or incomplete expansion of a lung or a portion of a lung, which is often the result of an obstruction or an accumulation of fluid in the pleural space but does not specifically denote the presence of air. Bronchitis is an inflammation of the bronchial tubes often associated with cough and mucus production, without any implication about pleural air presence. Empyema refers to the accumulation of pus in the pleural cavity, generally due to infection or inflammation, distinct from air presence. Thus, pneumothorax is the precise term that denotes air in the pleural cavity.