Coughing up sputum with occasional blood may be caused by the following diseases, such as acute upper respiratory tract infections, lung infections, lung tumors, etc. In addition, bleeding gums can also lead to this phenomenon. 1. Acute upper respiratory tract infection: common cold or acute pharyngolaryngitis, due to the stimulation of viral or physical and chemical factors, damage to the epithelial cells of the respiratory mucosa, resulting in severe coughing, which results in sputum with occasional blood. 2. Lung infections: pneumonia, tuberculosis, bronchial dilatation are all lower respiratory tract infections, lung infections are very common in the clinic, with bacterial infections at most, when the body’s immune system or other factors can lead to a decline in the lung’s defense function, resulting in lung infections. When lung infection occurs, it is better to determine the cause of infection and choose appropriate antibiotics for treatment. 3. Lung cancer: the causes of lung cancer are not yet completely clear, the main causative factors are smoking, air pollution, radiation, heredity, history of lung infection, etc. Smoking is the most common cause of lung cancer. In addition to dry cough with blood in sputum, lung cancer patients often suffer from emaciation, low fever, fatigue, anemia and other manifestations of tumor diseases. 4. Gingivitis: some people have bleeding gums, such as gingivitis, which will also be mixed with sputum and spit out. When the phenomenon of coughing with blood in sputum occurs, you should seek medical examination in time and take appropriate treatment according to the cause.