Bloody foamy sputum is a foamy sputum containing a large amount of blood. The sputum is red in color. Large amount of foamy sputum can be seen in pulmonary aspergillosis (sputum can smell like wine); pink foamy sputum is seen in pulmonary edema, etc. Chronic lung abscess, bronchiectasis, etc. may also have foamy sputum. What are the examination methods of pulmonary aspergillosis? 1, chest X-ray examination Allergic type shows increased lung texture or transient lung infiltration; invasive type shows bronchopneumonia changes; Aspergillus spheres are mostly located in the cavity, causing the cavity to be half-moon shaped air shadow, the spheres seem to pendulum-like can be moved with the change of body position. 2, sputum smear microscopy can see mycelium and spores; repeated positive sputum culture is helpful for diagnosis; allergic sputum can be found in a large number of eosinophils, blood total IgE increased. Sputum smear bacterial staining examination, often for Gram staining and antacid staining, is an important means of bacterial examination for respiratory diseases, detecting Streptococcus pneumoniae, Staphylococcus, S. pneumoniae or S. antacid, which is more meaningful for the diagnosis of the corresponding disease. Especially when only see a single kind of bacteria is more meaningful. 3, Aspergillus antigen skin test 4, serum precipitation test Immunoprecipitation reaction (Immunoprecipitation) is mainly used for the qualitative detection of antigens or antibodies. Its principle refers to the phenomenon of visible precipitates formed by soluble antigens and corresponding antibodies in the presence of electrolytes in appropriate proportions. The precipitation tests designed for this phenomenon include the flocculation test, the ring precipitation test and the in-gel precipitation test. The in-gel precipitation test can be divided into 2 categories, immunodiffusion test and immunoelectrophoresis technique, depending on the experimental method used.