Mycoplasma pneumoniae IgM antibodies are one type of Mycoplasma pneumoniae antibodies, and Mycoplasma pneumoniae antibodies also include IgG antibodies. Mycoplasma pneumoniae IgM is a very important serum indicator to confirm the diagnosis of mycoplasma infection, the reference value within 1:32 is within the normal range, if it exceeds this value, consider the current, recent presence of mycoplasma infection. A negative IgG antibody and a negative IgM antibody for Mycoplasma pneumoniae suggest that the patient does not have mycoplasma infection, but a single negative IgM and positive IgG indicates that the patient may have been infected with mycoplasma in the past, but it cannot be used as a basis for clinical diagnosis of mycoplasma infection, and the specific situation should be judged based on the patient’s symptoms.