Hemoptysis, or coughing up blood, is a common and significant symptom of pulmonary tuberculosis (TB). It occurs due to the destruction of lung tissue and erosion of blood vessels by the Mycobacterium tuberculosis infection. This leads to cavitary lesions that predispose the patient to bleeding. Hemoptysis reflects active pulmonary involvement and is a critical clinical sign for TB diagnosis and monitoring. Unlike jaundice, polyuria, or bradycardia, which are not linked to pulmonary pathology, hemoptysis directly indicates respiratory tract damage in TB.

Reference: Harrison's Principles of Internal Medicine, J. Larry Jameson, 20th Edition.