Pneumonia cannot be detected by blood tests. Pneumonia is an inflammation of the tissues of the lungs, which can be caused by a variety of pathogenic bacterial infections, with bacterial pneumonia being the most common. When bacterial pneumonia occurs, in addition to coughing, coughing up sputum, fever and other symptoms, in the blood routine is often manifested in the white blood cell count, neutrophil count is elevated. However, this change in blood count is not characteristic, and other bacterial infections, such as bronchitis, bronchial abscess, and bronchiectasis, can also present with this similar manifestation. A significant number of patients with pneumonia have low white blood cell counts and low neutrophil counts. Pneumonia caused by viruses is often low, and pneumonia caused by atypical bacterial infections, such as Mycoplasma pneumonia and Chlamydia pneumonia, do not have the characteristic changes in blood counts. In addition to the combination of clinical symptoms and blood tests, the diagnosis of pneumonia requires a chest X-ray or a CT scan of the lungs to confirm the diagnosis, and blood tests alone cannot detect pneumonia.