Mycoplasma pneumonia is an interstitial pneumonia caused by Mycoplasma pneumoniae. There are dozens of mycoplasmas that parasitize humans, but only Mycoplasma pneumoniae is pathogenic to humans. It has a high incidence in children and adolescents, with more incidences in the fall and winter. It is mainly spread by droplets and is often sporadic and occasionally epidemic. Patients have an acute onset with fever, headache, sore throat and persistent and severe cough, shortness of breath and chest pain, often with unremarkable sputum. White blood cell count: mildly elevated, with increased lymphocytes and monocytes. The disease is not easily distinguished clinically from viral pneumonia, but can be diagnosed by the patient’s sputum, nasal secretions and pharyngeal swab culture for Mycoplasma pneumoniae. Most mycoplasma pneumoniae have a good prognosis, with a mortality rate of 0.1-1%. Pathological changes: Mycoplasma pneumoniae infection can spread throughout the respiratory tract, causing upper respiratory tract infection, tracheitis, bronchitis and pneumonia. Pulmonary lesions often involve one lobe of lung tissue, more often the lower lobe, and occasionally both lungs. The lesions mainly occur in the interstitial lung, so the lesions are not obvious and are often stage-specific. The lesion is dark red to the naked eye, with a small amount of red foamy fluid overflowing from the cut surface and mucus exudate from the trachea and bronchial cavity. There was no exudate and only a small amount of plasma exudate mixed with mononuclear cells in the alveolar space. The walls of the small bronchi, fine bronchi and their surrounding interstitium are congested and edematous with chronic inflammatory cell infiltration, and in cases of bacterial infection there may be neutrophil infiltration. In severe cases, the bronchial epithelium and lung tissue may be markedly necrotic and hemorrhagic.