Test Directory

Study of adrenocortical-renin-angiotensin system; adrenal cortical function test; evaluate renal hypertension; diagnose Conn syndrome (primary aldosteronism); evaluate hypokalemia with hypertension.

Specimen Type: 24 Hour Urine

Collection Container: 24 Hour Plastic Urine Container

Desired Specimen Volume: 10 mL

1. Collect 24 hour urine in timed urine collection jug. Urine must be refrigerated during collection.

1. Transfer 10 mL of urine to clear aliquot tubes (screw caps).
2. pH of urine must be 4-8. pH may be adjusted by referral testing staff using 6M HCI.

If patient is taking diuretics, antihypertensive drugs, cyclic progestational agents, estrogen, or licorice, results for aldosterone may not be interpretable. Patient should be on a diet containing 135 mmol (3 g) sodium per day for at least two weeks and preferably 30 days prior to testing.

Transport to the laboratory refrigerated. 

• Incomplete 24-hour collection
• Original container with pH <2

 See patient report.

Urinary aldosterone measurements alone are of limited value in the diagnosis of hyperaldosteronism. Elevated levels mandate further investigation.