I. Epidemiological characteristics of dizziness and diagnostic problems Dizziness and vertigo are almost one of the most common clinical symptoms, with high incidence and prevalence, and are major syndromes in outpatient clinics of internal medicine, neurology and otolaryngology, as well as one of the major conditions in emergency departments. An annual National Health Service survey study in the United States showed that approximately 19.6% of people over the age of 65 had dizziness and balance disorders. This is comparable to data from another community-based and population-based survey in the United States and the United Kingdom (21%-29% prevalence). A Dutch survey of dizziness in all age groups showed an annual incidence of 4.7 per 1,000. The vast majority of dizziness is episodic, with less than 5% being persistent. The frequency of dizziness episodes varies across studies. In a community-based study of dizziness, 51% of people had monthly episodes, 14% had weekly episodes, and 35% had daily episodes. Despite the high incidence of dizziness, the diagnosis of dizziness by some clinicians is often “confusing” and “arbitrary”. The term “confusion” refers to the fact that some dizziness can be difficult to diagnose due to poor presentation or lack of experience by the patient; the term “arbitrariness” refers to the fact that physicians are more casual about diagnosing dizziness or vertigo of “unclear etiology”. The so-called “arbitrary” means that physicians give the diagnosis of “cerebral blood supply deficiency” or “cervical dizziness” to dizziness or vertigo of “unclear etiology” or simply use the word “dizziness” for symptomatological diagnosis, instead of conducting in-depth The diagnosis of dizziness and vertigo should be analyzed and considered in depth. For example, when a patient presents with dizziness or vertigo during head movement, the diagnosis often differs from one specialist to another, and some doctors often make a one-sided diagnosis based on their own opinion or from the perspective of their discipline. Some doctors consider cervical dizziness or cervical vertigo simply based on the presence of osteophytes and narrowing of the spinal space as shown by cervical spine X-ray; some diagnose arterial stenosis or spasm as a result of cerebral blood supply deficiency when they see transcranial Doppler ultrasound suggesting fast blood flow in a certain artery; some directly diagnose Meniere’s disease or vestibular peripheral vertigo based on simple vertigo; and some physicians generalize the diagnosis by “deficiency”. Some of them directly diagnose Meniere’s disease or vestibular peripheral vertigo based on simple vertigo; some other physicians generally use the word “deficiency” to argue the evidence. As a result, the same patient is diagnosed differently and given different treatment and medication as if he or she was “blinded by the elephant”, but with little effect, and some of them even get worse. Therefore, it is necessary to clarify the concept and diagnostic ideas of dizziness and vertigo. Second, the correct grasp of the concept of dizziness In 2009, Bisdorff et al Mo proposed a new classification of vestibular disorders. This new classification classifies vestibular symptoms into vertigo, dizziness (narrowly defined as non-vertigo dizziness), visual vestibular symptoms, and postural symptoms. Moreover, this classification has not been widely used because the more detailed classification associated with each symptom is very complicated and actually not particularly suitable for clinical operation. Broadly speaking, in 2010 Post and DickersonHl classified the concept of dizziness (dizziness) into the following four categories of conditions from a clinically practical perspective: dizziness (1ightheadedness), vertigo (vertigo), balance instability (disquilibrium), and presyncope (presyncope). This classification is very simple and easy to grasp for the diagnosis and treatment of dizziness. These symptoms occur when the patient is conscious. In other words, syncope, epilepsy, and other disorders that occur during loss of consciousness are not included. Thus, we understand that dizziness is a broad concept and that vertigo and dizziness are only a part of it. Dizziness is a paroxysmal or persistent feeling of lack of clarity in the brain, dizziness and dullness, head swelling, and a feeling of tightness in the head. High blood pressure and mental factors often cause dizziness. Dizziness may sometimes be a physiological process, not necessarily a pathological mechanism, such as lack of sleep, fatigue, long overnight shifts, etc., which can be corrected if adjusted at the right time. Dizziness is a symptom of illusion of motion of the patient’s subject to the static surrounding objects or his own position, which is mostly a pathological phenomenon. It is often manifested as a sense of rotation of visual objects or rotation of oneself, but it can also have a sense of swaying instability, undulating waves and falling. In general, patients are afraid to open their eyes during vertigo, often accompanied by nausea, and in severe cases, autonomic symptoms such as vomiting, excessive sweating, blood pressure fluctuations, etc. Some may be accompanied by nystagmus, ataxia, and other neurological localization signs. The pre-syncope state refers to the chest tightness, palpitations, dizziness, blackness, and weakness that occur before syncope. If upright hypotension occurs, the presyncope state is likely to occur. Unstable balance refers to dizziness symptoms with unstable standing or movement disorders in action. Therefore, patients who present to the clinic with dizziness should be distinguished as to whether they are dizzy and, if so, what type. Of course, for the individual patient, symptoms of dizziness can occur alone, simultaneously, or sequentially with symptoms of dizziness, vertigo, or unsteadiness of balance. Dizziness is generally divided into two categories: non-vestibular dizziness and vestibular dizziness. Non-vestibular system disease dizziness is mainly caused by medical system diseases [such as cardiovascular diseases (high and low blood pressure, arrhythmia), blood diseases (anemia, erythrocytosis), endocrine diseases], environmental changes and excessive activities (high temperature, heat stroke, prolonged standing, overwork, etc.), post-traumatic head injury syndrome, visual fatigue and ocular myopathy (such as myasthenia gravis, glaucoma, etc.), inflammation of the five senses (oral cavity, paranasal sinusitis), upper respiratory tract infections and drug effects or drug poisoning, peripheral nerve diseases, etc. In addition, it also includes psychogenic dizziness, such as depressive and anxiety states, mild mania, etc. These dizziness are not an involvement of the vestibular system per se. Most of them are dominated by dizziness, unstable balance, and pre-syncopal states. Vestibular system disorders are subdivided into central and peripheral dizziness. The main peripheral vestibular disorders include benign paroxysmal positional vertigo (BPPV), Meniere’s disease, vestibular neuronitis, labyrinthitis, and lymphangiolemmal leakage. Central vestibular system disease dizziness includes inadequate blood supply to the basilar artery, posterior circulation ischemia, cerebral hemorrhage, brain tumor, encephalitis or demyelinating disease, and vertiginous epilepsy. Others have both central vestibular involvement and peripheral vestibular involvement, such as migrainous vertigo (i.e. migraine isotonicity), which may have central symptoms such as visual field loss and transient blurred consciousness, and a few may have unilateral hemiplegia on peripheral vestibular examination. According to the latest domestic and international literature, the common causes of dizziness are BPPV, migrainous vertigo, psychogenic dizziness, non-vestibular system disease dizziness, posterior circulation ischemia or stroke. While conditions like Meniere’s disease, vestibular neuronitis or other central nervous system diseases (demyelination, tumor, inflammation) are among the less common cases of dizziness, cervical dizziness is less and less mentioned abroad, unless it is due to cervical hyperflexion and extension injury or neck trauma.