Lower respiratory tract infections, generally referred to as lung infections, often occur in coughing, coughing up sputum, fever, chest pain and other symptoms, most often caused by bacterial infections, fungal infections, mycoplasma or chlamydia, etc., depending on the cause of the disease can be given the appropriate medication for treatment. 1. Bacterial infection: Bacterial invasion of the lower respiratory tract may cause inflammatory lesions in the lower respiratory tract, which may cause coughing, and can be treated with antibiotics such as amoxicillin and levofloxacin to fight infection. 2. Fungal infection: fungal infection of lung tissue can cause fungal pneumonia, often with cough, cough sputum, sputum with blood and other symptoms, can use fluconazole, voriconazole and other antifungal drugs treatment. 3. Mycoplasma or Chlamydia infection: patients with mycoplasma or chlamydia infection caused by lung infection, mostly manifested as dry cough, can use erythromycin, azithromycin and other macrolide antibiotics treatment. The pathogens that cause lower respiratory tract infections may also be viruses, anaerobic bacteria and other pathogenic microorganisms, the need to improve the relevant laboratory tests after the cause of the disease to give targeted treatment, can be given at the same time to dextromethorphan and other medications to assist in the treatment of cough. It is recommended to consult a doctor in time, the above drugs should be standardized and rationally applied under the guidance of professional physicians and pharmacists.