Postural drainage is a technique used to drain excess mucus from the lungs using gravity and different body positions. Specific positions are used to drain different lung segments. During postural drainage, chest physiotherapy techniques like percussion and vibration are applied along with deep breathing and coughing exercises. Maintaining proper positions and performing chest physiotherapy helps drain mucus into the larger airways so it can be coughed up more easily, helping to prevent lung collapse and consolidation. Postural drainage is indicated for patients with excess mucus from conditions like chronic bronchitis or pneumonia and is contraindicated in some cases involving increased intracranial pressure or chest injuries.