In which condition is there a collection of fluid around the lungs?

The presence of fluid surrounding the lungs is known as pleural effusion. This condition occurs when excess fluid accumulates in the pleural space, the area between the lungs and the chest wall. Pleural effusion can result from various underlying causes, including heart failure, infection, malignancy, or inflammation, leading to symptoms such as shortness of breath, cough, and chest pain. Diagnostic imaging, like a chest X-ray or ultrasound, can detect this condition by revealing the fluid level in the pleural cavity.

Understanding the physiological process behind pleural effusion is crucial as it highlights the importance of the pleural space not only in lung mechanics but also in a range of pathologies that could require management or intervention. Conditions like pneumothorax involve air in the pleural space instead of fluid, and conditions like bronchitis and emphysema primarily affect the bronchial tubes and lung tissue itself rather than causing fluid accumulation in the pleura.