From the previous introduction, we can learn that the causes of vertigo are complex and involve many clinical departments, so it is very important to have a clear diagnosis of vertigo in order to achieve effective treatment and avoid the situation of “seeking medical help in an emergency”. 1.What information do I need to provide to the doctor after vertigo occurs? History taking is the most important part of vertigo diagnosis, and the information doctors need to know includes: 1. the time of the first occurrence of vertigo, the time of the last occurrence, the frequency of vertigo attacks, the duration of each vertigo; 2. the characteristics of vertigo (rotation of external objects or self rotation, floating sensation, shaking sensation, tilting), the presence of accompanying symptoms (headache, nausea, vomiting), and the presence of vertigo in specific positions History of ear disease: history of ear discharge, history of application of ototoxic drugs, any accompanying ear symptoms (hearing loss, tinnitus, ear fullness) during vertigo attack; 4. Neurological symptoms: numbness or movement disorder of face and limbs, speech difficulty, swallowing difficulty; 5. Triggers before vertigo (cold, overexertion, emotional changes); 6. Cervical spondylosis, ophthalmology, etc.; 7. Any family history of vertigo. 2. What tests should be done for vertigo? When patients with vertigo go to the hospital, doctors will usually do the following examinations and tests according to their conditions: general physical examination: identify whether there is any impairment of consciousness to distinguish syncope from vertigo; check blood pressure and pulse rate for hypertension or hypotension; check whether there is any pressure pain in the paracervical and cervical spine, whether there is herpes in the mastoid process, whether there is enlargement of the heart and arrhythmia, etc. Neurological examination: check whether there is spontaneous nystagmus, the type and direction of nystagmus; check whether there is edema of the optic papilla; check whether the eye moves in all directions, find out whether there is strabismus, diplopia, forehead wrinkling, eye closing, cheek puffing, teeth showing, check whether the facial nerve is paralyzed; check hearing, swallowing, whether there is choking, whether the tongue is crooked, to observe the function of the relevant cranial nerve. Finger-nose test, alternating movement and heel-knee-shin test can be performed to check whether the cerebellum functions normally or not. Laboratory tests: routine blood tests for anemia and infection, fasting blood glucose for diabetes and hypoglycemia, routine urine tests, liver and kidney functions, thyroxine and parathyroid hormone, etc. If intracranial hemorrhage is suspected, cerebrospinal fluid should be drawn to confirm the diagnosis of various diseases. Imaging tests: transcranial Doppler examination (TCD), cervical vascular ultrasound, cranial CT, temporal bone CT, cranial magnetic resonance imaging (MRI), magnetic resonance flow imaging (MRA), etc. In addition, there are audiology and vestibular function tests, which are very important tests for vertigo and are non-invasive and not harmful to human body. 3.What is nystagmus? What is its clinical significance? Nystagmus is called nystagmus for short. Peripheral lesions, central lesions and certain eye diseases in the vestibule can cause spontaneous nystagmus, so nystagmus examination can help to understand the situation of vestibular lesions. Nystagmus is an involuntary rhythmic movement of the eye, and vestibular nystagmus consists of alternating slow-phase and fast-phase movements. The slow phase is a slow movement of the eye in a certain direction, caused by vestibular stimulation, while the fast phase is a rapid return movement of the eye, which is a central corrective movement. The slow phase of eye movement is directed toward the side of lower vestibular excitability, and the fast phase is directed toward the side of higher vestibular excitability. Because the fast phase is easy to observe, the direction of the fast phase is usually used as the direction of nystagmus. According to the direction of nystagmus, it can be divided into horizontal nystagmus, vertical nystagmus and rotational nystagmus. According to the intensity of nystagmus, it can be divided into 3 degrees: Ⅰ° nystagmus only appears when looking to the fast phase side; Ⅱ° nystagmus appears when looking to the fast phase side and forward; Ⅲ° nystagmus appears when looking forward and to the fast and slow phase directions. 4.What are the common audiological examinations? Why is it necessary to do audiological examination? Many vertigo diseases, such as Meniere’s disease, sudden deafness with vertigo, etc., have hearing impairment, and audiological examination can help to confirm the diagnosis of the above diseases, as well as evaluate the degree and nature of hearing loss and guide the use of medication. Pure tone hearing threshold test: ① can determine the nature of hearing loss: conductive deafness, sensorineural deafness, mixed deafness. ② Judgment of the degree of hearing loss: the degree of hearing loss refers to the WHO hearing impairment grading standard (2006), and the average thresholds of the patient’s binaural air conduction 0.5 KHz, 1 KHz, 2 KHz and 4 KHz are calculated respectively. mild hearing impairment: 26~40 dB HL; moderate: 41~60 dB HL; severe: 61~80 dB HL; very severe: >80 dB HL. ③ Hearing curve of type: high frequency hearing decline type, rising type, flat type, valley type, tangent type. (2) Acoustic conductance: tympanic chamber curve diagram, stapedius muscle acoustic reflex (the difference between acoustic reflex threshold and pure tone hearing threshold ≤ 60 dB can be judged to have reverberation phenomenon). In addition, there are auditory brainstem response, aberrant otoacoustic emission, cochlear electrogram, etc.