Each 1 ng/dL increase in aldosterone corresponded to 4% higher odds of hypertension in 999 postmenopausal women aged 66 years from the Study of Women's Health Across the Nation (SWAN), with 52% prevalence of hypertension overall. The association remained significant after adjusting for age, race, BMI, physical activity, smoking, and cholesterol levels. This finding illuminates a potential mechanism behind the poorly understood blood pressure rise that occurs in midlife women. Aldosterone, the primary mineralocorticoid hormone, regulates sodium retention and blood volume—making this connection biologically plausible. The research adds to mounting evidence that subclinical aldosterone excess, even within normal ranges, may drive cardiovascular risk in postmenopausal women when estrogen's protective effects wane. However, this observational study from a preprint awaiting peer review cannot establish causation, and the 4% per-unit increase represents a modest effect size. The lack of association with treatment-resistant hypertension suggests aldosterone's role may be more relevant for mild-to-moderate hypertension. For women navigating menopause, this reinforces the importance of blood pressure monitoring and lifestyle interventions that naturally support healthy aldosterone balance, including potassium-rich diets and stress management.