There are many reasons for not coughing up blood in sputum. Blood in sputum is mainly seen in bronchial diseases, lung diseases and cardiovascular diseases.
1. Bronchial diseases: common in bronchial dilatation, bronchial lung cancer and bronchial tuberculosis and other diseases. The mechanism is that inflammation, tumor and stones cause rupture of bronchial submucosal blood vessels or increase of capillary permeability, thus leading to blood in sputum.
2. Lung diseases: common in tuberculosis, pneumonia and lung abscess and other diseases. The mechanism is that tuberculosis and inflammation increase the permeability of capillaries or rupture the wall of submucosal blood vessels, thus leading to blood in sputum.
3. Cardiovascular diseases: common in mitral stenosis, pulmonary hypertension, pulmonary embolism and pulmonary vasculitis and other diseases. The mechanism is mostly pulmonary stasis resulting in alveolar wall capillary rupture or bronchial endothelial capillary rupture, which leads to blood in sputum.
4. Others: hematological diseases such as leukemia, hemophilia and thrombocytopenic purpura, rheumatic diseases such as systemic lupus erythematosus and leukemia, and certain acute infectious diseases such as epidemic hemorrhagic fever, can lead to blood in sputum.
Repeated serious blood in sputum may also have other problems, should be timely to the regular hospital consultation, clear cause of the disease and follow the doctor’s instructions for targeted treatment.