Early, accurate, and secure diagnosis is critical in IPFexacer bated patients with reversible precipitating [7] . For details about laboratory tests and blood/sputum/bronchoalveolar lavage (BAL) tests, see the 'Clinical and laboratory assessment' section. Cardiac echo, cardiac echocardiography; CTPA, computed tomography pulmonary angiography; HRCT, high-resolution computed tomography; ICU, intensive care unit; PE, pulmonary embolism; PH, pulmonary hypertension; PNX, pneumothorax; proBNP, pro-brain natriuretic peptide. factor(s) (Figure 1 ) [2] . Investigation into medical history should focus on smoking habits, toxic exposures, prescribed medications, immunosuppression, and signs and symptoms of potentially undiagnosed autoimmune rheumatic disease [2, 54, 55] . Physical examination frequently reveals tachypnea, cyanosis, digital clubbing, bilateral inspiratory crackles, and lower extremity edema. In the most severe cases, the patient may be obtund or comatose because of severe hypoxemic and potentially hypercapnic respiratory failure. Th e presence of arrhyth mias, chest pain, hemoptysis, or hemodynamic instability should guide the physician to an overlapping or alternative diagnosis such as acute coronary syndrome or pulmonary embolism.