Elevated calcitoninogen indicates a high probability of bacterial infection and is now considered to be closely related to bacterial infection and is a specific indicator of bacterial infection. If calcitoninogen is mildly elevated, it means that there may be a mild bacterial infection, and the more pronounced the elevation, the more serious the infection, and when it is significantly elevated, the greater the likelihood of sepsis. Localized infections rarely result in elevated calcitoninogen, and clinical analysis is often combined with routine blood work, C-reactive protein, and calcitoninogen to determine whether a patient has a bacterial or viral infection. Usually, calcitoninogen is not significantly elevated in viral infections. Other causes can affect calcitoninogen, but they are not as pronounced as those caused by bacterial infections.