Premonitory syncope is a relatively common vasovagal syncope in young people and is very common. It often recurs, especially when under considerable emotional stress, extreme fatigue, pain, panic, or in crowded, hot rooms. Since the blood vessels in other parts of the body are not innervated by the vagus nerve except the heart, some scholars have recently suggested that the term neurocardiogenic syncope may be more appropriate. So, how to diagnose syncope prognosis? The following are the diagnostic methods of syncope: For a long time, the diagnosis of definite syncope has been indirect, time-consuming and expensive, and often without clear results. The upright tilt test is a new test developed in recent years and plays a decisive role in the diagnosis of syncope prognosis. The positive reaction is the occurrence of syncope with a significant drop in blood pressure or heart rate after the patient is tilted from a prone to an upright position during the test. The mechanism of the upright tilt test for the diagnosis of vasovagal syncope is not fully understood. It has been suggested that bradycardia caused by inhibitory reflexes is due to vagal mediation, whereas hypotension caused by resistance vasodilation and volume vasoconstriction is the result of sympathetic inhibition. One study reported that in patients with recurrent presyncope, flexion and extension exercises of the arms and legs during prodromal symptoms helped prevent syncope, which may be related to increased venous blood return by skeletal muscle pump action. Increasing fluid and sodium intake may also help prevent syncope from occurring.