What do you mean by severe illness?

Severe illness actually refers to the severity of this disease.

Intensive care unit is a unit that specially treats critical diseases and gives careful monitoring and precise treatment.

Critical Care Medicine (CCM) is a medical professional discipline, which takes critical illness as the main research object, based on the combination of basic medicine and clinical medicine, uses modern monitoring and intervention technology as the method, comprehensively understands critical illness and finally improves the survival rate of critical patients through effective treatment measures. That is, critical care medicine is the theoretical basis of intensive care unit, and intensive care unit is the clinical practice base of critical care medicine.

The monitoring scope of the intensive care unit is very wide, which can be divided into respiratory system, circulatory system, liver system, brain system, kidney system, gastrointestinal system, blood and coagulation system, endocrine system, water electrolyte system and oxygen supply system. Commonly used monitoring items include ECG, cardiac function, blood pressure, respiratory frequency and rhythm and pattern, body temperature, urine volume, arterial blood gas analysis, EEG and so on. According to the severity of the disease, the monitoring range is divided into three levels, with first-level monitoring for patients in special care, second-level monitoring for patients who may be in fatal danger after illness and operation, and third-level monitoring for patients whose condition tends to be stable.

above content reference: Baidu Encyclopedia-Intensive Care (Intensive Care)