The most important lung diseases that cause vomiting of blood are bronchiectasis, tuberculosis, and pulmonary malignancies. Bronchiectasis is a structural lung disease, due to repeated chronic inflammatory infections, resulting in structural changes in the bronchial tubes, persistent dilatation, when the inflammatory infection foci involve small arteries, there will be symptoms of vomiting blood. Tuberculosis is also caused by mycobacterium tuberculosis, when the lesion involves small veins or arteries, the symptoms of vomiting blood will also appear. Malignant tumors of the lungs can also cause vomiting of blood when the tumor invades the bronchial arteries or pulmonary arteries. Different treatments should be adopted according to different causes.