Aldosterone/renin (ARR) is the ratio of aldosterone to renin activity, reflecting the relative activity of the two.The ARR is used primarily for the diagnosis of primary aldosteronism and to differentiate it from primary hypertension. The ARR also reflects the degree of renin inhibition by aldosterone due to the presence of the hormonal axis renin-angiotensin II-aldosterone. Primary aldosteronism is defined as an increase in aldosterone secretion due to adrenocortical pathology, leading to secondary hypertension and hypokalemia, and an increase in ARR due to suppression of the renin-angiotensin system. an ARR ratio >30 suggests that primary aldosteronism is likely to be present, and >50 is of some diagnostic significance. It is recommended that the patient should consult the doctor in time, according to the ARR results, combined with the aldosterone value and other comprehensive judgment, and follow the doctor’s instructions for further examination and treatment.