The main symptoms of pneumonia are fever, cough, and coughing up sputum. If you can’t cough up sputum, there are four factors: first, drinking too little water, sputum is more sticky, then you can drink more water or do saline nebulization, pat your back, and use sputum chemistry medicine. Second, the physical condition is poorer inability to cough, lung function decreases, coughing airflow is smaller, and phlegm is not easy to cough out, also try to make the phlegm more dilute after with the machine of sputum discharge and lung patting to promote phlegm discharge. Thirdly, it is related to pathogen infection, for example, virus and mycoplasma mainly invade the interstitial lung and affect the airway relatively less, so the amount of sputum produced will be less and there will be no coughing up of sputum. Fourthly, the lesion is more on the periphery of the lung, and the sputum produced in this case is less likely to reach the large airways, so the sputum is not easy to cough up or the coughing sputum is particularly small.