Chapter 2: Pulmonology

The content systematically addresses infectious pulmonary diseases, beginning with pneumonia as an inflammatory condition of the lung parenchyma caused by bacterial, viral, or fungal pathogens, with particular attention to common causative organisms and antibiotic selection based on patient risk factors. Tuberculosis is presented as a chronic mycobacterial infection requiring prolonged antimicrobial therapy and epidemiological investigation. Upper airway infections including epiglottitis and croup are covered as acute, potentially life-threatening emergencies, while acute bronchitis and bronchiolitis are addressed as viral inflammatory conditions of the conducting airways. The neoplastic disease section examines bronchogenic carcinoma as the leading cause of cancer mortality, distinguishing between small cell and non-small cell histologic subtypes with their differing treatment approaches and prognosis. Solitary pulmonary nodules and carcinoid tumors are discussed regarding malignancy risk stratification and management protocols. The obstructive disease category encompasses asthma as a chronic inflammatory condition with reversible airway obstruction, chronic obstructive pulmonary disease including emphysema and chronic bronchitis, and bronchiectasis characterized by progressive bronchial dilation and airway destruction. Restrictive and miscellaneous pulmonary conditions include cystic fibrosis as a genetic disorder affecting mucociliary clearance, pleural effusions and spontaneous pneumothorax requiring fluid or air removal, and pulmonary embolism as a vascular occlusive emergency. The chapter concludes with inflammatory and fibrotic conditions including sarcoidosis and occupational lung diseases, along with acute respiratory distress syndrome as a critical care complication. Throughout the chapter, diagnostic approaches using imaging, laboratory testing, and clinical assessment are integrated with evidence-based therapeutic interventions appropriate to each disease entity.