Severe infectious bronchitis may occasionally cause blood to appear in the septum. Hemoptysis may also be due to bronchogenic carcinoma. Cancerous growths often have a rich blood supply, and they frequently bleed into neighbouring tissues. In addition, a cancer that is rapidly enlarging can damage already existing blood vessels. If a patients cancer is near the bronchial surface, blood may spill into the bronchial tree and be coughed upward (i.e., hemoptysis).