Haemoptysis and vomiting blood are both discharged through the mouth, but the difference is big, the main difference is: 1, haemoptysis: the respiratory bleeding below the larynx is coughed up through the mouth, mostly caused by coughing, the haemoptysis is bright red, mixed with sputum, and the old haemoptysis is dark red, accompanied by clots and blood in sputum; haemoptysis is most common in pulmonary tuberculosis, bronchial dilatation, and lung cancer, etc.; 2, haematochezia: it is the bleeding of upper gastrointestinal tract, and there are obvious symptoms of vomiting, and the haematochezia usually mixed with gastric fluid, which is in the shape of coffee colour or coffee residue, and the large quantity of haematochezia can be in the shape of bright red or dark red and the bleeding quantity is bigger; the haematochezia is mostly found in the peptic ulcers, cirrhosis of the liver, etc;