To compare the diagnostic value of three confirmatory tests for primary aldosteronism.

This is a prospective study involving 240 hypertensive patients who underwent primary aldosteronism screening. Every patient will undertake four confirmatory tests to compare the diagnostic accuracy of the oral sodium loading test with captopril challenge testing (CCT) and Seated saline infusion test(SSST)using the fludrocortisone suppression testing (FST) as the reference standard, and to investigate the optimal cutoff of oral sodium loading test

Inclusion Criteria:

1. hypertensive patients with ARR≥10(pg/ml)(uIU/ml)
2. hypertensive patients with ARR<10(pg/ml)(uIU/ml) but suspicious of PA clinically

Exclusion Criteria:

1. Pregnancy or lactation;
2. Child-bearing women refuse to take effective contraceptive measures;
3. History of malignant tumor;
4. Patients with cardiovascular and cerebrovascular diseases (eg. myocardial infarction, acute heart failure, stroke), in the past 3 months
5. NYHA III (New York Heart Association)and above
6. Hypohepatia
7. Chronic kidney disease with an estimated Glomerular Filtration Rate <30ml/min/1.73 m²
8. Severe arrhythmia by ECG or severe heart disease by cardiac ultrasound
9. Patients who are unwilling to participate in and complete this study and refuses to sign the informed consent form for this study

hypertensive patients being suspicious of PA in a single tertiary hospital center