Arterial hypertension(AH)is the most relevant risk factor for acute cerebrovascular disease in general.However,the prevalence of AH is not the same for the different stroke subtypes and is particularly high in lacunar infarcts and atherothrombotic stroke,low in infarcts of unusual cause and undetermined origin,and intermediate in cardioembolic stroke.This risk factor has also been related to vascular dementia and Alzheimer’s disease and their pathological manifestations(senile plaques,neurofibrillary tangles,hippocampal atrophy).The mechanisms linking AH to Alzheimer’s disease remain to be elucidated but some recent studies showed that white matter lesions seen on cerebral magnetic resonance imaging appear to be a good marker of this association.Hypertension-associated pathological changes in the brain and its vasculature include vascular remodelling and impaired cerebral autoregulation like hypoperfusion,ischemia and hypoxia,which may initiate the pathological process of Alzheimer’s disease and the expression of dementia.Therefore,prompt diagnosis and adequate control of hypertension and different vascular risk factors are the rational basis for a more effective strategy in the secondary prevention of cerebrovascular disease and dementia.