Syncope is a transient impairment of consciousness caused by a brief lack of blood supply to the brain, which can be recovered in seconds or tens of seconds. Because of the sudden onset of the patient, family members or bystanders are often at a loss for words, and the patient often recovers completely after being taken to the hospital with no abnormalities on various tests. There is too little evidence for doctors to make a diagnosis, and often the cause cannot be found even after multiple episodes. The first-hand information obtained by witnesses is very helpful in diagnosis. 1. The condition of the seizure For example, whether the face is pale during the seizure, the breathing rhythm, the pulse rate, whether it is fast or slow, whether it is uneven, whether there is any change in the pupils, whether the eyes are upturned, whether there are convulsions, falls, urinary and fecal incontinence, and the performance before and after the seizure. Find out under what circumstances the seizure occurred, whether there were any triggers, whether there were any psychological factors, whether there was any relationship with defecation or coughing, and the position at the beginning of the seizure. Episodes of hypoglycemia, hyperventilation, hysteria, hypertension, and cardiogenic syncope are not related to body position. Upright hypotensive syncope occurs within a short time after rising from a recumbent or squatting position. Syncope occurs suddenly within a few seconds and may be due to some serious arrhythmia, such as severe heart block, cardiac arrest, or tachycardia. Gradual occurrence within minutes should be considered hysteria and hypoglycemic syncope. 2, the time and frequency of seizures: seizure time more than a few minutes suggests hypoglycemia, hysteria, hyperventilation. Several episodes in a day should be considered cardiac disease with arrhythmia. 3. Accompanying symptoms: Seizures with pale face, cold sweat, nausea and other manifestations are mainly seen in hypoglycemia. Those with significant twitching of the limbs are most often seen in epilepsy, but also in severe arrhythmias, such as paroxysmal ventricular fibrillation or cardiac arrest. If accompanied by irregular twitching or generalized spasms without loss of consciousness or EEG changes, it is commonly seen in hysteria. Slow breathing with snoring is seen in brain-derived syncope. Brain lesions must also be considered in those presenting with neurological signs.