Final answer:
To distinguish between cardiac and pulmonary causes of dyspnea, medical professionals use lab tests that measure acid-base balance, chest radiographs, auscultation for heart and lung sounds, as well as other specialized tests such as bronchoalveolar lavage and HRCT.
Step-by-step explanation:
Lab tests to distinguish between cardiac and pulmonary causes of dyspnea can include several diagnostic tools. For example, acid-base balance measurements (such as blood pH, CO2 partial pressure, and HCO3-) can indicate whether dyspnea is due to a respiratory or metabolic problem and the extent of any compensatory mechanisms. Chest radiographs can identify structural abnormalities in the lungs, such as pneumonia, that might cause dyspnea. The presence of crackles heard during auscultation, abnormal heart sounds, and the results of blood tests (such as sputum cultures or blood samples) contribute to diagnosing the underlying condition. Additional tests like bronchoalveolar lavage (BAL), pulmonary function tests, and high-resolution computed tomography (HRCT) are used to diagnose conditions such as hypersensitivity pneumonitis.
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