Hypertension: A Proximal Clinical Signature and Promoter of Early Cardiorenal Disease?

Hypertension has traditionally been viewed as a hemodynamic disorder leading to cardiac and renal injury; however, growing evidence suggests that, in many individuals, elevated blood pressure is instead the earliest clinical expression of subtle cardiorenal dysfunction. Early abnormalities—such as low-grade albuminuria, increased renal resistive index, arterial stiffness, and masked or nocturnal hypertension—can appear before estimated glomerular filtration rate decline or elevated office blood pressure, indicating early impairment of pressure–natriuresis, heightened tissue renin–angiotensin–aldosterone system (RAAS) activity, and increased renal microvascular impedance. The aim of this review is to summarize mechanistic, clinical, and phenotypic evidence supporting the concept that hypertension functions as an early biomarker along the cardiorenal continuum. Incorporating vascular and renal biomarkers, ambulatory blood pressure phenotyping, and targeted laboratory indices into routine assessment may identify individuals transitioning from functional disturbances to structural organ damage. These abnormalities reflect a mechanistic triad of arterial stiffening, salt-sensitive RAAS activation, and circadian blood pressure disruption, collectively defining the early cardiorenal–hypertensive phenotype. Viewing hypertension through a cardiorenal lens underscores a critical opportunity for earlier detection and mechanism-oriented intervention, which may modify disease trajectory and prevent progression to overt chronic kidney disease and heart failure.