Hemoptysis can be caused by diseases of the airways, particularly bronchitis or bronchiectasis. Other causes include bronchogenic carcinoma, metastatic cancer or bronchial carcinoid. Kaposi's sarcoma involving the airways may cause hemoptysis in patients infected with HIV. Hemoptysis can also arise from the lung parenchyma. Autoimmune diseases (such as SLE, mixed connective tissue diseases, etc.), cocaine inhalation, and infections (including tuberculosis, bacterial pneumonia, and lung abscess), as well as pulmonary embolism, pulmonary arteriovenous malformation, mitral stenosis, severe left heart failure, and Wegener's granulomatosis should also be included in the differential diagnosis of hemoptysis.
Teaching topics from the New England Journal of Medicine - Vol. 358, No. 6, February 7, 2008