A severe infection is a life-threatening infection, which is a systemic side effect caused by the multiplication of disease-causing microorganisms in the human body, causing organ insufficiency in one organ or the whole body. The main clinical manifestation is the phenomenon of systemic organ insufficiency and failure of systemic organ function, called severe infection. Serious infections can include many, such as severe pneumonia, serious abdominal infections, urinary tract infections, skin infections, and central nervous system infections, all of which often lead to systemic organ dysfunction and then life-threatening and fatal. First of all, we should know that we usually have a lot of contact with pathogenic microorganisms, and there are many pathogenic microorganisms in the normal environment, and we have our own defense system. The key is to pay enough attention to minor illnesses in daily life and to seek timely medical attention for minor illnesses.