Gas poisoning mainly refers to carbon monoxide poisoning, clinical performance and exposure time, concentration, the patient’s basic state has a relationship, the performance does not have specificity, as follows: 1, mild poisoning will have a headache, dizziness, nausea, vomiting and other manifestations, out of the poisoned environment after inhalation of fresh air can be relieved; 2, moderate poisoning will generally have a severe headache, nausea, vomiting and even blurred vision, vision or The performance of moderate poisoning will have severe headache, nausea, vomiting and even blurred vision, vision loss or judgment decline, but generally will not appear consciousness disorder or after oxygen therapy, quickly return to normal; 3, severe carbon monoxide poisoning performance can have different degrees of consciousness disorder, nausea, vomiting, aspiration and even cerebral edema, pulmonary edema or multi-organ failure, can also appear convulsions. Inhalation of high concentrations of carbon monoxide poisoning at one time, death can occur. The patient is in a coma, which indicates that the poisoning is severe. Generally, the longer the coma, the worse the prognosis is, and the patient is often left with dementia, memory loss, loss of comprehension, hemiplegia and other sequelae.