Approach to dyspnea

• Tempo: seconds (PE, pneumothorax), hours-days (pneumonia, failure), months (COPD, ILD, anemia)
• Orthopnea and PND (cardiac); positional or exertional
• Chest pain character; cough and sputum; hemoptysis
• Risk inventories: smoking, VTE risks, cardiac history, exposures

• Work of breathing and ability to speak
• JVP, S3, edema (the cardiac column)
• Air entry, wheeze, crackles, dullness (the pulmonary column)
• Calves, and conjunctivae for pallor

Acute pleuritic dyspnea with hypoxia and a clear chest in a post-operative patient (points at PE) versus subacute orthopneic dyspnea with a raised JVP and crackles (points at failure).

• SpO2 and blood gas when saturation or mentation is off
• ECG and troponin where cardiac weight exists
• CXR: the single highest-yield image
• NT-proBNP when failure versus lung is genuinely uncertain
• Wells-gated D-dimer or CTPA for PE weight
• CBC for anemia; PFTs for the chronic outpatient course

• Hypoxia with a clear exam and film pushes toward PE or early shunt physiology
• The gas splits ventilation failure (high PaCO2) from oxygenation failure (wide A-a gradient)
• The trend of work of breathing outranks any single number

• Treat the threat first (oxygen, then the specific lesion)
• Every dyspnea gets a named leading diagnosis and a stated reassessment time