The main diagnosis of viral pneumonia is based on clinical manifestations and chest imaging, followed by blood tests and sputum tests. 1. Clinical manifestations: It often occurs in the epidemic season of viral diseases, and the symptoms are usually mild. Generally, the onset of the disease is rapid, often with fever, generalized pain, fatigue, sore throat and other symptoms, and in severe cases, there may be respiratory distress, cyanosis, or even shock, respiratory failure or acute respiratory distress. 2. Chest imaging: chest X-ray is commonly used, which can show increased lung texture, glassy shadow, small patchy infiltration or extensive infiltration, solid changes, and in severe cases, it can show diffuse nodular infiltration in both lungs. CT manifestation is more diversified, and it is common to see hairy glass shadows and small nodular foci. 3. Blood test: patients with viral pneumonia may have normal, slightly high or slightly low white blood cell count and normal blood sedimentation. Serum test for specific antibody is helpful for early diagnosis. Double serum antibody titer in acute and recovery phase is more than 4 times higher than that of acute and recovery phase, which has diagnostic significance. 4. Sputum examination: Generally, sputum culture has no growth of pathogenic bacteria and is often used to exclude non-viral pneumonia.