Pleural effusions are common, but working through them systematically can be challenging. In this episode, we take a deep dive into pleural fluid analysis, starting with a clear and practical breakdown of Light’s criteria and how it’s used to differentiate transudative from exudative effusions. We review the key laboratory values, common pitfalls, and why these criteria remain so central to clinical decision-making.

From there, we explore the major etiologies of transudates and exudates, linking physiology and pathology to real-world causes such as heart failure, infection, malignancy, and inflammatory disease. Throughout the discussion, we emphasize clinical reasoning—showing how to synthesize history, imaging, and lab results to arrive at a thoughtful diagnosis.

Whether you’re a student learning pleural effusions for the first time or looking to reinforce a structured approach, this episode aims to make pleural fluid analysis more intuitive, practical, and clinically meaningful.