Positive Legionella pneumophila, indicating infection with Legionella pneumonitis, most can be cured, but some patients are not treated in time, will be further progression, serious cases may be life-threatening. Legionella pneumonitis, lung inflammation with a more acute onset, clinical pneumonia as the main manifestation, often accompanied by multi-system damage, but according to the patient’s individual physical condition of the severity of the disease is different, the clinical performance varies greatly. Some patients may experience sudden high body temperature, cough, chest pain, limb pain, dyspnea, and some may experience cough, hematemesis, bloody sputum and other symptoms. Severe patients may experience altered mental status, blurred consciousness, headache, drowsiness, speech disorders, and gait disorders. The treatment of Legionella pneumonitis usually chooses macrolide antibiotics, such as azithromycin, erythromycin or quinolone antibiotics for anti-infective treatment, and if there are symptoms of high fever, you can choose ibuprofen, acetaminophen, and other medications for symptomatic treatment, and at the same time timely correction of electrolyte disorders, improve ventilation. Generally, after active and timely treatment, lung function can be basically restored to normal, but a few patients may have fibrosis. If the patient has other serious diseases, long-term use of immunosuppressive drugs, or is older, the prognosis is poorer, and in severe cases, the patient’s life may be jeopardized. Legionella pneumonitis should be examined in a regular hospital in time for early detection and treatment, and all medications should be used under the guidance of a professional doctor.