Past medical history should cover disorders known to cause dyspnea, including asthma, COPD, and heart disease, as well as risk factors for the different etiologies: Smoking history—for cancer, COPD, some interstitial lung diseases, and heart disease Family history, hypertension, and high cholesterol levels—for coronary artery disease Recent immobilization or surgery, recent long-distance travel, cancer or risk factors for or signs of occult cancer, prior or family history of clotting, pregnancy, oral contraceptive use, calf pain, leg swelling, and known deep venous thrombosis—for pulmonary embolism Occupational exposures (eg, gases, smoke, asbestos) should be investigated.