Aging plays a critical role in the development of cerebral small vessel disease (CSVD), contributing to vascular cognitive impairment (VCID) and dementia. CSVD is associated with blood-brain barrier (BBB) disruption, neuroinflammation, and white matter damage, which are frequently observed as white matter hyperintensities (WMHs) in neuroimaging. Older adults with atherosclerotic vascular diseases, such as peripheral artery disease, ischemic heart disease, and carotid artery stenosis, are at higher risk of developing CSVD and VCID. This review explores the complex relationship between peripheral atherosclerosis, CSVD pathogenesis, and BBB disruption, emphasizing shared pathomechanisms that underlie atherosclerosis in large arteries and BBB disruption in the cerebral microcirculation. These mechanisms exacerbate both CSVD and VCID. The review discusses the impact of endothelial dysfunction, cellular senescence, inflammation, and oxidative stress on vascular and neurovascular health. It also highlights the role of BBB disruption in the pathogenesis of VCID, the shared mechanisms between atherosclerosis and BBB disruption, and the clinical implications of these processes. The review emphasizes the importance of understanding the continuum of vascular aging, linking peripheral atherosclerosis to BBB disruption and CSVD. It also discusses the role of atherogenic diets, circulating factors, and endocrine influences in the pathogenesis of atherosclerosis and BBB disruption. The review concludes that vascular health is crucial for maintaining neurovascular integrity and preventing cognitive decline. The findings underscore the need for integrated approaches to manage vascular health to mitigate the risk and progression of CSVD and VCID.Aging plays a critical role in the development of cerebral small vessel disease (CSVD), contributing to vascular cognitive impairment (VCID) and dementia. CSVD is associated with blood-brain barrier (BBB) disruption, neuroinflammation, and white matter damage, which are frequently observed as white matter hyperintensities (WMHs) in neuroimaging. Older adults with atherosclerotic vascular diseases, such as peripheral artery disease, ischemic heart disease, and carotid artery stenosis, are at higher risk of developing CSVD and VCID. This review explores the complex relationship between peripheral atherosclerosis, CSVD pathogenesis, and BBB disruption, emphasizing shared pathomechanisms that underlie atherosclerosis in large arteries and BBB disruption in the cerebral microcirculation. These mechanisms exacerbate both CSVD and VCID. The review discusses the impact of endothelial dysfunction, cellular senescence, inflammation, and oxidative stress on vascular and neurovascular health. It also highlights the role of BBB disruption in the pathogenesis of VCID, the shared mechanisms between atherosclerosis and BBB disruption, and the clinical implications of these processes. The review emphasizes the importance of understanding the continuum of vascular aging, linking peripheral atherosclerosis to BBB disruption and CSVD. It also discusses the role of atherogenic diets, circulating factors, and endocrine influences in the pathogenesis of atherosclerosis and BBB disruption. The review concludes that vascular health is crucial for maintaining neurovascular integrity and preventing cognitive decline. The findings underscore the need for integrated approaches to manage vascular health to mitigate the risk and progression of CSVD and VCID.