Patients with normal blood count may also develop pneumonia, and patients with pneumonia usually need to have their blood count checked. Pneumonia with normal blood work is most often due to mild lung infections, or in patients with immunosuppressed states, or in patients with infections caused by viruses, mycoplasma, chlamydia, or legionella, etc. Therefore, the diagnosis of pneumonia should not be based on blood work alone. Patients mostly need to undergo chest imaging, mainly chest X-ray or CT, when new inflammatory lesions are found to infiltrate, along with exclusion of non-infectious lesions, when this can be considered the presence of pneumonia. The presence of pneumonia also needs to be diagnosed in conjunction with the patient’s clinical symptoms, physical examination, and other relevant tests. It is also important to note that the severity of pneumonia should not be assessed solely on the basis of routine blood results.