ICU syndrome refers to a group of syndromes that occur during the course of ICU care in patients with predominantly psychiatric disorders and other manifestations. Patients have a variety of manifestations and varying degrees of severity, but the main focus is on psychiatric disorders with other concomitant symptoms. The main symptoms are: 1) delirium, which is the most common symptom of the disorder and is characterized by a marked decrease in responsiveness to external stimuli. 2) thought disorder, which can be manifested both through language and behavior. 3) affective disorder, which is manifested by emotional exaltation and euphoria in a small number of patients and emotional depression in most patients. 4) behavior and movement disorder, which is characterized by abnormal behavior and movement, such as shouting, tearing clothes and destroying objects, hitting others. 5.Intelligence disorder, dementia often occurs in the process of ICU monitoring, which also belongs to intelligence disorder. 6.Other manifestations, such as insomnia, headache, constipation, diarrhea, etc.