PCT, known as calcitoninogen in Chinese, is a very common infection indicator used in clinical practice. PCT levels in blood can be detected by taking a small amount of blood and measuring it using a fluorescent immunoassay. The PCT level inside normal human blood is almost zero, and it will rise when an infection occurs in the body. Most PCT tests in tertiary care hospitals cost about 200-300 yuan, and there may be some subtle differences in some hospitals. When the body has some viral, bacterial, fungal, parasitic infections PCT will be significantly higher, especially for sepsis, septicemia, PCT can rise very significantly, if the condition improves in the process of anti-infection treatment, PCT will fall.