Aldosterone
An adrenal hormone that regulates sodium retention, potassium excretion, blood volume and blood pressure.
Primary aldosteronism is the most common correctable cause of resistant high blood pressure — and it's massively under-diagnosed. Worth checking in anyone with hypertension that won't respond to treatment, or with unexplained low potassium.
Potassium must be measured on the same draw — the guideline says so explicitly, because hypokalemia both suppresses aldosterone secretion and flags the diagnosis. The thresholds above assume the draw was handled correctly: posture, time of day, sodium intake and a long list of antihypertensives all move both halves of the ratio, and a ratio calculated on a suppressed renin approaching zero is arithmetically unstable no matter how good the assay is. This is the clearest case on the site of a marker where the pair has a guideline-anchored threshold and the single number has nothing.
Check a Aldosterone result against this range →
What Aldosterone actually measures — the analyte, and the assay
Aldosterone is almost never interpreted alone; it is interpreted as the top of a ratio. The aldosterone-to-renin ratio divides plasma aldosterone by either plasma renin activity or direct renin concentration, and those two denominators are different measurements in different units, so a ratio cut-off is only meaningful with its renin method attached Ariens 2022.
The aldosterone itself comes from an immunoassay or from LC-MS/MS, and they disagree in a way that matters most where the decisions are made. A controlled study measuring the same samples by both methods under multiple physiological conditions found the relationship between them changes across the physiologic range, which is why interpretations had to be recalibrated rather than simply converted Brown 2022. A single conversion factor does not exist.
Renin is the more fragile half. Plasma renin activity is an enzyme assay: it measures angiotensin I generated per hour, so it depends on incubation temperature and on how the sample was handled. Cold storage of whole blood cryoactivates prorenin and raises the measured activity — a plasma renin sample must not be put on ice.
Posture is part of the method, not part of the patient. The standardized collection is seated for 5 to 15 minutes after 2 hours upright, in the morning, and a sample taken outside that protocol is not comparable to the reference data Yang 2024.
Aldosterone: what changes the blood, and what only changes the reading
What changes the aldosterone in you:
- Sodium intake. A low-sodium diet raises aldosterone several-fold; a high-sodium diet suppresses it. This is the largest single influence and it is dietary, not pathological.
- Volume status and posture. Standing, dehydration, diuretics and hemorrhage all raise it through renin.
- Potassium. Aldosterone secretion is directly stimulated by potassium and suppressed by hypokalemia — which is why a patient with untreated hypokalemia can have a falsely reassuring aldosterone Yang 2024.
- Time of day. Secretion follows ACTH in the early morning and falls through the day.
- Autonomous production, which is the thing the test exists to find, and which is far more common than the classical teaching implies Yang 2024.
What changes the ratio without changing the adrenal:
- Antihypertensive drugs, in both directions. Beta-blockers suppress renin and inflate the ratio; ACE inhibitors, angiotensin receptor blockers and diuretics raise renin and deflate it. The confounders of the ratio used as a screening test have been catalogued formally Veldhuizen 2021, and the drugs conventionally called neutral are not perfectly neutral either — verapamil, hydralazine and doxazosin each move renin, aldosterone or the ratio to some degree Veldhuizen 2023.
- Spironolactone or eplerenone, which raise renin and make the ratio uninterpretable for weeks after stopping.
- Estrogen-containing contraceptives, which raise angiotensinogen and therefore plasma renin activity, but not direct renin concentration — so the same person screens differently depending on which renin method the laboratory runs Veldhuizen 2021.
- A very low renin. The ratio's denominator approaches zero, so the ratio explodes on arithmetic alone; this is why most protocols require a minimum aldosterone concentration as well as a high ratio Ariens 2022.
- Which aldosterone assay. Immunoassay and mass-spectrometry values are not interchangeable across the range Brown 2022 Lorde 2023.
- Posture, hour and salt intake on the day of the draw, none of which usually appears on the report.
Reference interval or decision threshold — which kind of number Aldosterone is
The aldosterone interval is a reference interval measured under conditions almost nobody reproduces. It assumes a defined posture, hour and sodium intake. Printed beside a sample collected at 3 p.m. after a salty lunch, it is a range from a different experiment.
The ratio cut-off is a screening decision threshold, and it was chosen for sensitivity. Its performance in unselected primary care populations is materially worse than in the referral series that defined it Ariens 2022, which is the classic behavior of a threshold moved to a lower-prevalence setting.
A positive screen is not a diagnosis and was never meant to be. Confirmatory testing — saline suppression, fludrocortisone suppression or captopril challenge — exists because the ratio alone produces too many positives Yang 2024.
The disease itself turns out to be a spectrum rather than a category, with autonomous aldosterone production running from biochemically overt down through milder degrees that the classical thresholds miss Yang 2024. That is an argument about where the line should be, not about whether one exists.
How you would know your Aldosterone was wrong — and when to redraw
Repeat only after the collection conditions have been fixed, and that usually means a drug washout. Four to six weeks off mineralocorticoid receptor antagonists, and 2 weeks off beta-blockers, diuretics, ACE inhibitors and angiotensin receptor blockers where blood pressure allows, is the standard because the ratio's biggest confounders are pharmacological Veldhuizen 2021 Veldhuizen 2023.
Correct potassium before redrawing. Hypokalemia suppresses aldosterone secretion, so a normal aldosterone in a hypokalemic person is uninformative rather than reassuring Yang 2024.
Conditions that must match: the same morning hour; the same posture protocol; the same renin method — activity and concentration are not convertible Ariens 2022; the same aldosterone method Brown 2022; and an unrestricted sodium intake.
What would have to change for the second number to mean something:
- Ratio high, aldosterone low? The renin is doing the work and the finding is a suppressed renin, not an aldosterone excess. Most protocols will not act without an aldosterone above a minimum Ariens 2022.
- Ratio high with hypokalemia? The confirming numbers are potassium and bicarbonate inside the CMP, plus a formal suppression test — not a repeat ratio.
- Aldosterone high with a high renin? That is secondary, and the causes are renal or volume-related: check creatinine and eGFR in the CMP and urinalysis for protein.
- Everything borderline? Repeating the ratio on a different day, off interfering drugs, is one of the few situations where a simple redraw genuinely changes the answer Veldhuizen 2021.
What Aldosterone cannot tell you
It cannot localize anything. A confirmed aldosterone excess still requires imaging and, in most surgical candidates, adrenal venous sampling to say which side Yang 2024.
It cannot be interpreted on most antihypertensive regimens, and the drugs that most commonly bring a person to this test are the drugs that most distort it Veldhuizen 2021 Veldhuizen 2023.
It cannot be compared between laboratories. Different aldosterone methods, different renin methods and different units make two ratios from two laboratories different quantities Brown 2022 Lorde 2023.
A normal ratio does not exclude the condition in someone with hypokalemia, on a mineralocorticoid antagonist, or with a milder autonomous phenotype Yang 2024.
The wrong inference readers actually draw is that aldosterone is a stress or adrenal-health number to be optimized. It is a volume and potassium regulator whose value on any given day is mostly set by salt intake, posture and medication, and its only established clinical use is as one half of a screening ratio for a specific, treatable cause of high blood pressure Ariens 2022 Karashima 2022.
Sources read for these sections
- Brown JM, et al. Recalibrating Interpretations of Aldosterone Assays Across the Physiologic Range: Immunoassay and Liquid Chromatography-Tandem Mass Spectrometry Measurements Under Multiple Controlled Conditions. Journal of the Endocrine Society 2022 · PMID 35475027
- Veldhuizen GP, et al. Confounders of the aldosterone-to-renin ratio when used as a screening test in hypertensive patients. Journal of Clinical Hypertension 2021 · PMID 33368994
- Veldhuizen GP, et al. The Effects of Verapamil, Hydralazine, and Doxazosin on Renin, Aldosterone, and the Ratio Thereof. Cardiovascular Drugs and Therapy 2023 · PMID 34515895
- Ariens J, et al. Performance of the aldosterone-to-renin ratio as a screening test for primary aldosteronism in primary care. Endocrine 2022 · PMID 35622194
- Yang J, et al. Challenges in Diagnosing and Managing the Spectrum of Primary Aldosteronism. Journal of the Endocrine Society 2024 · PMID 38887633
- Karashima S, et al. Rapidity and Precision of Steroid Hormone Measurement. Journal of Clinical Medicine 2022 · PMID 35207229
- Lorde N, et al. Impact of Variation between Assays and Reference Intervals in the Diagnosis of Endocrine Disorders. Diagnostics (Basel) 2023 · PMID 37998589
Where to start with Aldosterone
In this order. Start at the supplement and you learn nothing, because you never established the number was real.
You have the range, where it came from and the first two moves. Inside is the rest of the five-pathway protocol — supplements, hormones, peptides — the order to run them in, and what to change when the number will not move.
Get the full protocol — $10/mo →📚 Endocrine Society CPG — Primary Aldosteronism: Case Detection, Diagnosis and Treatment.
🩸 Test your Aldosterone
Order directly through Marek Diagnostics — no doctor's visit needed, drawn at any Quest location in the US. Code CAMERON applies 10% off automatically.
Order this test — 10% off → Browse all 103 markers →What Aldosterone is usually tested alongside
One marker is a data point. These panels add the markers that make Aldosterone interpretable, name why each is on the list, and load the set into your cart at 10% off.
includes this + 8 more markers — Anyone under about 45 with high blood pressure, anyone whose pressure needs three or more drugs to control, and anyone whose potassium has been running low without an obvious reason.
includes this + 7 more markers — Wired-and-tired, crashing mid-afternoon, salt cravings, dizzy on standing, or you've been told you have 'adrenal fatigue'.
What people use Aldosterone to decide
Nobody orders a test for its own sake. Aldosterone is on the test list for these pathways — each one links to what the pathway claims, and what its test list is read for before you spend anything on it.
The rhythm is the diagnosis, not the level. Worth being blunt: 'adrenal fatigue' is not a recognized condition and the glands rarely fail — but a flattened cortisol curve is real, measurable and treatable.
ADMA inhibits nitric oxide synthase directly, so it is the most specific endothelial marker available. Dysfunction here precedes visible plaque by decades.
Would you feel it? Symptoms Aldosterone helps explain
People search for how they feel, not for a marker. These are the complaints where this one is worth checking, and whether it is first-line or a follow-up.
Why your Aldosterone might be wrong
Most abnormal results are interference, not disease. Check these before you change anything. Each says whether the number is wrong (repeat it), badly timed (redraw it), or real with a cause.
Aldosterone roughly doubles on standing. Upright and supine reference ranges are completely different numbers.
The draw must record your posture, and the aldosterone-to-renin ratio is the actual screening test.
Spironolactone, ACE inhibitors, ARBs, beta-blockers and diuretics all distort the aldosterone-renin ratio, in different directions.
This test needs planning with a doctor — several drugs must be stopped for weeks beforehand.
Both alter aldosterone substantially. Low potassium suppresses it, which can mask primary aldosteronism.
Correct potassium before testing.
What Aldosterone means in combination
One marker tells you a little; combinations tell you the story. These are the named patterns this one takes part in.
Primary aldosteronism, the most common curable cause of high blood pressure and one almost nobody screens for. It carries higher cardiovascular and kidney risk than blood-pressure-matched essential hypertension, and it has specific treatment.
Confirm with an aldosterone-to-renin ratio, planned with a doctor — several blood pressure drugs distort it and need stopping first. Correct potassium before testing, because low potassium suppresses aldosterone and can mask the diagnosis.
What to test next
These put Aldosterone in context — each with its own full breakdown.
Frequently asked questions
Upright 4–31 ng/dL; varies with posture, sodium intake and time of day. Ranges vary by laboratory and assay — always compare to the range printed on your own report.
Mid-range with normal potassium and blood pressure. Interpreted as the aldosterone:renin ratio, not alone. Endocrine Society Clinical Practice Guideline on Primary Aldosteronism, 2025 update.
Hypertension, low potassium, muscle cramps and weakness. Warrants endocrine workup with the aldosterone:renin ratio.
Low blood pressure, salt craving, elevated potassium.
You can order Aldosterone directly through Marek Diagnostics without a doctor's visit — drawn at any Quest Diagnostics location in the US. Code CAMERON applies 10% off automatically.
Where this goes next
This page is the free framework. The protocol itself — the dosing, the order to correct things in, the week-by-week schedule and what to retest — is a lesson inside Skool.