Most patients with somatic infections present with mild and transient psychiatric symptoms, such as difficulty concentrating, mild disturbances in consciousness, anxiety, depression, irritability, insomnia or drowsiness, and mental fatigue. A small number of patients may develop more severe psychiatric disorders. During acute infection, it often manifests as syndromes such as disorders of consciousness and delirium; while in chronic infection, it mainly manifests as amnesia syndrome or dementia. The etiology and pathogenesis of mental disorders due to somatic infections differ, including: direct and toxin effects of pathogenic microorganisms (bacteria p viruses, etc.) on the central nervous system, cerebral circulation disorders, metabolic disorders of the body, fever, water and electrolyte disturbances and side effects of drugs. In addition, the functional status of the body, such as the immune system, endocrine system and the patient’s pre-morbid personality characteristics and genetic predisposition, are also factors that affect the development of mental disorders. Mental disorders caused by physical diseases often have common characteristics: the onset is rapid and the course of the disease is often fluctuating, for example, the patient feels tired and mildly dizzy in the morning, and may become anxious and irritable in the afternoon, while confusion occurs in the evening. In addition, psychiatric symptoms are usually closely related to the infection, and when the infectious disease improves, so do the psychiatric symptoms. Timely detection of the primary infectious disease is essential for proper diagnosis. If a patient presents with impaired consciousness and acute cognitive dysfunction, especially disorientation and clouding of consciousness, full attention should be paid and the primary somatic disease should be actively sought. Early diagnosis and early treatment are very important because psychiatric symptoms can aggravate the symptoms of somatic diseases, such as agitated behavior can worsen cardiovascular system diseases, and it is not conducive to water and nutrition absorption, etc. Therefore, treatment should be two-pronged, treating the primary illness while controlling the psychiatric symptoms. Clinical medication should be used with caution, paying particular attention to hepatic and renal impairment, water-electrolyte disorders and interactions between psychotropic drugs and other medications.