PCT, known in Chinese as procalcitoninogen, is a very common indicator of infection used in clinical practice. The level of PCT in the blood can be detected by taking a small amount of blood and using fluorescent immunoassay to determine the level of PCT in the blood. The level of PCT in normal human blood is almost zero, but it rises when the body is infected. Most of the PCT tests in tertiary hospitals cost around 200-300 RMB, with some slight differences in some hospitals. When the human body has some viral, bacterial, fungal, parasitic infections, PCT will rise significantly, especially for sepsis, sepsis, PCT can rise very significantly, if the condition improves in the course of anti-infective treatment, PCT will fall.