The concept of age-related dementias and vascular disorders has now been recognized for over a century. In the present review, we have emphasized on the causes, consequences and the true bases for the treatment and prevention of these disorders. Systematic efforts have been put together to identify the aetiology in each case. Increased efforts have been targeted towards the concept and genetic factors responsible for vascular cognitive impairment and post-stroke dementia in relation with Alzheimer's disease, which is a consequence of age-related dementia, especially as they hold promise for early prevention and treatment. It has now been well accepted that vascular dementia is not a single disease but a group of conditions with different pathological correlations and pathophysiological mechanisms. The present review represents an amalgamation of several pathophysiological mechanisms producing a very heterogeneous clinical presentation for developing such consequences. We suggest current diagnostic categories and describe clinical parameters according to recently reported studies that document the demographic data in a standardized manner for age-related dementia disorders.