Pulmonary candidiasis is an acute, subacute or chronic pneumonia caused by Candida albicans or other Candida species. Candida has the property of adhering to mucosal tissues, among which Candida albicans is particularly strong in adhering to tissues, so its pathogenicity is more serious than other Candida. After being phagocytosed, Candida can still grow budding tubes in macrophages, penetrate cell membranes and damage macrophages. Candida can also produce pathogenic water-soluble toxins, which can cause clinical shock. In recent years, there is an increasing trend of non-Candida albicans (such as Candida tropicalis, Candida smoothis, Candida klebsiella, etc.) infections. There are two types of pulmonary candidiasis, which are also two stages in the development of the disease process. I. Candida bronchitis Paroxysmal irritating cough, coughing up a lot of thin sputum like white foam, occasionally with blood, with the progress of the disease, sputum thick as dry glue. Breathlessness and shortness of breath, especially at night. X-rays only show thickened texture in the middle and lower fields of both lungs. Candida pneumonia Clinical manifestations are chills, high fever, coughing white foamy mucous sputum with fermented odor, or jelly-like, sometimes hemoptysis, clinically similar to acute bacterial pneumonia. Chest X-ray shows increased texture in both lower lungs and fibrous streaks with scattered nodular shadows of varying size and shape, showing bronchopneumonia; or fused uniform large infiltrates, extending from the hilum to the periphery, which may form cavities. In bilateral or multilobar lesions, the lesions may be variable, but the lung apices are less frequently involved. Occasionally, it may be complicated by exudative pleurisy. Candida can be detected in the sputum of healthy individuals. To diagnose pulmonary candidiasis, more than 3 consecutive sputum cultures with Candida growth and mycelium detected in smears or pathogenicity proven by animal inoculation are required. In order to exclude contamination by Candida parasiticus in the pharynx, sputum specimens should first be gargled several times with 3% hydrogen peroxide solution, discard the first two sputum, take the subsequent sputum specimens and send them for culture immediately. It is also possible to take the aspirate via bronchoscope or tracheal tube for examination. It should be noted that sputum should not be stored at room temperature for too long, otherwise there may also be mycelial growth. Serum Candida-specific IgE antibody assay is useful for diagnosis, and is a sensitive test for the presence of serum precipitins in the serum, usually 14 days after infection. However, histopathological evidence is still needed to confirm the diagnosis. In mild cases, the condition often improves gradually after eliminating the causative factors, while in severe cases, antifungal drugs should be applied promptly. Fluconazole 200mg daily, double the first dose, or 400mg/d in severe cases, or even higher doses, 6-12mg/(kg/d). Amphotericin B can also be used in severe cases, 0.6-0.7mg/(kg/d), but the toxicity reaction is large and should be selected clinically according to the patient’s status and fungal drug sensitivity results.