Mycoplasma pneumoniae antibodies are divided into IgM and IgG. The normal value of IgM is between 0 and 1.1, and exceeding 1.1 means that the mycoplasma antibodies are IgM positive. The IgM antibodies appear early at this time, one week after Mycoplasma pneumoniae infection, peaking at 3-4 weeks and gradually decreasing later. Since the incubation period of Mycoplasma pneumoniae infection is 2-3 weeks, IgM antibodies are already at a high level by the time the patient presents with symptoms and seeks medical attention. Therefore, if there is a positive IgM antibody, it can be used as a diagnostic indicator of acute phase infection. At this time, if coughing and sputum are present, a CT chest examination must be done to rule out bronchitis or pneumonia caused by Mycoplasma pneumoniae. If these conditions exist, hospitalization is required, and intravenous macrolide antibiotics, such as azithromycin or erythromycin, are more effective during hospitalization.