Sudden vertigo in the elderly may be caused by benign positional vertigo, cerebral blood supply insufficiency, cerebral infarction, cervical spondylosis and other causes. 1. Benign positional vertigo: it is usually caused by the change of head position, resulting in otolith dislodgment to the semicircular canals, thus causing sudden vertigo, which may be accompanied by nystagmus, nausea and vomiting and other symptoms. 2. Insufficient cerebral blood supply: If there is serious cerebral atherosclerosis in the elderly, resulting in thickening of blood vessel walls and narrowing of blood vessel lumens, leading to slow blood flow, resulting in ischemia and hypoxia of brain tissues, sudden dizziness may be caused, which may be accompanied by headache, nausea and other symptoms. 3. Cervical spondylosis: common in vertebral artery type and sympathetic nerve type, due to the stimulation and compression of vertebral artery, resulting in insufficient blood supply to the vertebral artery leading to vertigo, which may be accompanied by neck pain, nausea, vomiting and other symptoms. 4. Cerebral infarction: Vertigo symptoms can occur when the cerebellum or brainstem is infarcted, and is usually accompanied by speech disorder, limb movement disorder and ataxia. Sudden dizziness in the elderly, it is recommended to consult a doctor as soon as possible to clarify the cause of the disease and then targeted treatment.