What's going on when I suddenly cough up blood?

Suddenly coughing up blood is usually caused by bronchial disease, lung disease, cardiovascular disease and some other types of diseases, and the appearance of bleeding symptoms indicates that the condition has reached a relatively serious level. Therefore, patients must not ignore the symptom of coughing up blood. No matter how much blood is coughed up, they must go to the hospital for examination in time and then receive appropriate treatment.

1. Bronchial diseases

Common ones include bronchiectasis, bronchial lung cancer, bronchial tuberculosis and chronic bronchitis; rare ones include bronchial stones, bronchial adenoma, nonspecific ulcers of bronchial mucosa, etc. Its occurrence mechanism is mainly due to increased permeability of bronchial mucosa or capillaries caused by inflammation, tumors, and stones, or rupture of submucosal blood vessels.

2. Lung disease

Common ones include pulmonary tuberculosis, pneumonia, lung abscess, etc.; less common ones include pulmonary congestion, pulmonary embolism, pulmonary parasitic disease, pulmonary fungal disease, alveolitis, pulmonary hemosiderosis and good health syndrome. Hemoptysis caused by pneumonia is common in pneumococcal pneumonia, Staphylococcus aureus pneumonia, Klebsiella pneumoniae pneumonia and Legionella pneumonia. Mycoplasma pneumonia may sometimes also cause blood in the sputum. In our country, the leading cause of hemoptysis is still pulmonary tuberculosis. Pulmonary tuberculosis that causes hemoptysis is mostly infiltrative tuberculosis, cavitary tuberculosis and caseous pneumonia, while acute hematogenous disseminated tuberculosis rarely causes hemoptysis. The mechanism of hemoptysis due to pulmonary tuberculosis is that tuberculosis lesions increase capillary permeability, causing blood to seep out, resulting in blood or small blood clots in sputum; if the lesions involve small blood vessels and rupture the tube walls, moderate hemoptysis will be caused; if small aneurysms formed by pulmonary artery branches in the cavity wall rupture, or arteriovenous fistulas formed by secondary tuberculous bronchiectasis rupture, massive hemoptysis will be caused, even life-threatening.

3. Cardiovascular disease

The most common cause is mitral stenosis, followed by pulmonary hypertension or primary pulmonary hypertension caused by congenital heart disease, as well as pulmonary embolism, pulmonary vasculitis, hypertension, etc. Hemoptysis caused by cardiovascular disease may manifest as small amounts of hemoptysis or blood in sputum, large amounts of hemoptysis, pink foamy bloody sputum, and thick dark red bloody sputum. Its occurrence mechanism is mostly due to pulmonary congestion causing rupture of alveolar wall or bronchial endothelial capillaries and rupture of bronchial varicose veins in the submucosal layer of the bronchial mucosa.

4. Others

Hematologic diseases (such as leukemia, thrombocytopenic purpura, hemophilia, aplastic anemia, etc.), certain acute infectious diseases (such as hemorrhagic fever, pulmonary hemorrhagic leptospirosis, etc.), rheumatic diseases (such as polyarteritis nodosa, systemic lupus erythematosus, Wegener's granulomatosis, Behcet's disease, etc.), or tracheal and bronchial endometriosis can all cause hemoptysis.