Sputum is usually seen when treating respiratory tract infections, which mostly suggests that the treatment is effective. Respiratory tract infections are generally due to bacterial and viral infections, coughing, sputum and other symptoms, can be treated by infusion, such as anti-infective, phlegm and other drugs to improve the discomfort, the general infusion of pathogens on the respiratory tract can be killed gradually kill, and at the same time to promote the respiratory tract of the accumulation of secretions out of the body, so the infusion of sputum will be outwardly sputum, suggesting that the condition has improved. For patients with respiratory tract infections coughing sputum, it is recommended to drink more water, increase nutrition, reduce the intake of stimulating foods; if the infusion of non-respiratory tract infections, and the emergence of sputum outward, it is recommended to actively seek medical attention to clarify the cause of the disease after treatment.