Some school-age children often experience: dizziness, dizziness, blurred vision, etc. They may also experience nausea, sweating and hyperventilation, etc. Some tests are often normal. What can be done? Here we will explain what is syncope in children and what we parents should do if we encounter it. Syncope refers to a transient, self-limiting impairment of consciousness caused by insufficient blood supply to the brain and transient cerebral hypoxia, accompanied by a loss of voluntary muscle tone. Usually occurs more suddenly, can not maintain a standing position and fainting, generally lasts for a few seconds to a few minutes, if the loss of consciousness for a long time, may occur the phenomenon of twitching of the limbs. When consciousness is restored, the face is still pale, the body is weak, and there is reluctance to speak or move, or there is nausea, yawning, hyperventilation, bradycardia, headache, etc. Classification of syncope Syncope is a common emergency in childhood, and about 15% of children experience syncope with underlying diseases including autonomic-mediated syncope, cardiogenic syncope, and cerebrovascular syncope, among which autonomic-mediated syncope is the most common underlying disease in children with syncope, accounting for about 80% of cases, including vasovagal syncope, postural tachycardia syndrome, upright hypotension, and situational syncope. In recent years, epidemiology has shown an increasing trend in its incidence. Diagnosis and differential diagnosis of syncope Children with autonomic-mediated syncope are most often seen in adolescent girls, occur in a standing position, have obvious precipitants before the attack, and often have significant syncopal aura symptoms. Children with cardiogenic syncope often have a history of heart disease, have a young age of onset, have insignificant aura symptoms before the onset of syncope, and exercise can trigger the onset of syncope; electrocardiography, Holter and echocardiography are valuable for its diagnosis. Cerebrovascular syncope needs to be clarified with the help of EEG, cranial imaging, neurological signs and medical history. Our hospital is the first in the province to adopt the classical basic upright tilt test for the diagnosis of autonomic-mediated syncope in children. The upright tilt test is divided into the basic upright tilt test and the drug-induced upright tilt test. The principle is When the human body goes from the horizontal to the upright position, there is a transfer of blood from the thoracic great vessels to the lower extremities, which is equivalent to a kind of endogenous blood loss, and the central venous pressure, heart beat output and arterial pressure tend to decrease, which activates the intra-arterial (carotid sinus and aortic arch) and cardiopulmonary pressure receptors, and the signal is transmitted to the medullary center, leading to enhanced sympathetic activity, and also activates the RAS (renin angiotensin) and vasopressure system, as a result: vasoconstriction, increased heart rate, enhanced myocardial contractility, increased cardiac output, this endogenous blood loss is compensated and blood pressure is maintained. In contrast, in patients with autonomic-mediated syncope, reduced return blood volume and inadequate ventricular filling cause sympathetic excitation and increased blood catecholamines, resulting in strong contraction of the left ventricle and excitation of pressure receptors in the posterior wall of the left ventricle. The afferent signal is too strong, and to relieve the excessive myocardial contraction and ventricular wall tension, the parasympathetic inhibitory efferent signal increases, and as a result, hypotension and/or bradycardia and syncope occur. Nitroglycerin is a vasodilator-based drug that enhances lower extremity venous blood stasis induced by the upright position and reduces the amount of return blood, thereby triggering autonomic-mediated syncope, is well tolerated, easy to use, easy for the child to cooperate with, and has few side effects, and its clinical value has been recognized by most scholars. Treatment of syncope The treatment of syncope in children should be standardized, etiologic and individualized as the basic principle, with the main goal of preventing recurrence of syncope and injuries caused by syncope, reducing the risk of death and improving the quality of life. Treatment measures include: autonomic function exercise and physiotherapy, increased salt and fluid intake therapy, pharmacotherapy, pacing therapy, radiofrequency ablation therapy, etc. Prognosis of syncope The mortality rate of cardiogenic syncope is significantly higher than that of noncardiogenic syncope. For children, the main triggers for syncope occurrence include prolonged standing, hot and stuffy environment, mental stimulation, etc. To avoid syncopal attacks in children, families should try to avoid being in various triggers that cause syncopal attacks. When syncope occurs, immediately lying down position, head to the side, within a few minutes can perform relief; when the aura of syncope occurs, immediately self-regulation, such as taking a flat position, elevate the lower limbs, take a sitting or squatting position, etc.. Parents need to pay attention to the children who encounter syncope, step by step investigation, and target the cause of the disease will not be wrong.