Drug intoxication should be differentiated and diagnosed from cerebrovascular accident, cardiogenic pulmonary edema and pulmonary encephalopathy by brain CT, magnetic resonance imaging, angiography, chest CT, cardiac ultrasound, lung auscultation and lung imaging. 1. Patients with cerebrovascular accident usually have signs of cerebral nervous system localization such as hemiparesis, sensory impairment, aphasia, or increased intracranial pressure such as coma, headache, and projectile vomiting, etc. Cerebrovascular accident patients should be examined by brain CT, magnetic resonance imaging, and angiography to see if there are organic lesions in the cerebrovascular system, and differentiate them from drug intoxication. 2. cardiogenic pulmonary edema patients have chronic heart failure or heart disease basis, there will be sudden dyspnea, sitting breathing and coughing pink foamy sputum and other manifestations, through the cardiac ultrasound to see whether the heart is enlarged, chest CT to see whether there are two lungs hairy glass shadows, lung portal enlargement and other pulmonary edema manifestations, as well as lung auscultation whether there are wet rales, and drug poisoning to differentiate the judgment. 3. Pulmonary encephalopathy patients mostly have chronic bronchitis, chronic obstructive pulmonary emphysema and other lung diseases, when accompanied by infection, can cause pulmonary hypoxic encephalopathy and lead to confusion, further aggravate the respiratory difficulties, combined with the patient’s medical history and lung imaging to identify and judge with drug intoxication. Drug intoxication is a toxic reaction to an overdose of a drug in a short period of time or to an accumulation of drugs from prolonged exposure. Patients may experience clinical symptoms such as cyanosis, coma, mental abnormalities, dyspnea and asphyxia. It is recommended that when the patient develops the above symptoms, he/she should be sent to the hospital promptly for treatment and differentiated from other diseases under the guidance of the doctor.