Feeling that there is phlegm inside the lungs that cannot be coughed out is mainly common in some diseases of the respiratory system, such as acute attack of chronic bronchitis, acute bronchitis, pneumonia, etc. At this time, you can test the blood routine and take X-ray or CT of both lungs to clarify the diagnosis. Due to the decrease of body resistance and invasion by pathogens such as viruses or bacteria, the airways below the pharynx, such as the trachea, bronchi, and alveolar mucosa of the lungs appear obvious inflammatory reaction of congestion, edema and exudation of inflammatory substances. At this time, you can gargle and rinse your throat with salt water every day, and if necessary, you can also take some expectorant drugs, such as carboxymesterol oral solution and tranylcypromine syrup. In combination with bacterial infection, antibiotics can be used appropriately, such as amoxicillin, cefuroxime, clindamycin, levofloxacin and other drugs.