Normal blood white blood cells do not necessarily mean that there is no inflammation. Some viral infections, infections treated with glucocorticoids, etc. may have normal or even reduced white blood cell levels. Since white blood cells are the main cells involved in the immune response in the body, white blood cell levels can generally reflect inflammatory infections in the body, but mainly for bacterial infections. For simple viral infections, white blood cells may be insignificantly elevated or normal, when they can be detected by viral nucleic acid tests, for example. Meanwhile, for some serious infections using drugs such as glucocorticoids, the white blood cell level may also be normal due to the inhibitory effect of the drugs, but clinical symptoms such as fever may still exist. This can be determined by testing calcitoninogen, or imaging to detect foci of infection in the body. If infection is suspected, further investigation and treatment in a hospital is recommended.