Age-related open-eye coma is caused by damage to the thalamus, suboptic thalamus, superior brainstem, cortical cingulate gyrus, or corpus callosum, while the function of the motor nerve is preserved and the patient’s eyes turn from time to time. The orienting reflex to sound and the transient reflex to visual stimuli are present, but the response to nociceptive stimuli is very sluggish and may elicit only the defensive reflexes of the limbs. The patient does not speak, does not move, is unable to communicate thoughts, sleeps for a long time, has sweating and temperature disturbances, and is polyuric, a vegetative state. There are many causes of coma. In addition to coma due to secondary brain dysfunction caused by metabolic and extracranial other systemic diseases, the common causes in neurology are as follows: 1. Diffuse brain lesions (1) Various CNS-specific or non-specific infections, such as encephalitis, meningitis, etc. (2) Extensive craniocerebral trauma. (3) Subarachnoid hemorrhage. (4)Drug poisoning. 2. Focal brain lesions (1) Various intracranial occupying lesions: ① brain abscess, subdural pus or fluid accumulation, meningitis, encephalitis; ② traumatic acute and chronic subdural hematoma, epidural hematoma, intracerebral hematoma, cerebral contusion, cerebral edema, etc.; ③ various intracranial tumors or metastases; ④ hypertensive cerebral arteriosclerotic cerebral hemorrhage. (2) Cerebrovascular disease: ① cerebral hemorrhage. ② cerebral infarction or cerebral embolism. (3) Hypertensive encephalopathy. (3) Intracranial pressure elevation syndrome. (4) Continuous status epilepticus, etc.