When a patient is diagnosed with pneumonia, the causative microorganism is evaluated and the appropriate treatment is administered depending on the causative microorganism. Common pathogenic microorganisms in clinical practice include bacteria, viruses, and atypical pathogenic bacteria. If a patient presents with elevated white blood cells, C-reactive protein, and calcitoninogen, a bacterial infection is considered at this time and requires treatment with antibiotics. In mild cases, oral cefixime, amoxicillin, and other related antibiotics are given. In severe cases, cefazolin sodium, cefodizime, levofloxacin, etc. can be administered intravenously. If the patient has decreased white blood cells, positive viral antibody or viral nucleic acid test, antiviral or antipyretic drugs, such as Abidor, Oseltamivir, Lianhua Qingfei capsule, Qingkai Ling, etc., can be used, and symptomatic treatment can be given. If the pneumonia is caused by atypical pathogenic bacteria, oral antibiotics such as macrolides or quinolones can be administered.