Hypertension and chronic kidney disease frequently coexist and mutually accelerate cardiovascular and renal injury. This narrative review prioritizes direct human autonomic phenotyping (Level 1: microneurography, HRV/BRS), human vascular correlates (Level 2: PWV, FMD), and complementary preclinical evidence (Level 3) to elucidate autonomic-vascular mechanisms. Autonomic imbalance, characterized by sympathetic overactivity and reduced parasympathetic restraint, represents a key interface between