Primary Aldosteronism: Screening, Surgery vs Drugs and Funding

Table of contents

• Evidence summary
• What primary aldosteronism is
• Symptoms and red flags
• Causes and risk factors
• How common is it?
• Testing and screening
• Treatments that work, with evidence
• Surgery versus spironolactone
• Medicines
• Supplements and lifestyle claims
• Risks and side effects
• Who to see
• Follow the money
• Related research
• Frequently asked questions
• Sources and funding notes

Evidence summary

Independent evidence and credibility scorecard

Independence tiers: 1 = regulator or government body; 2 = academic or Cochrane team with no declared commercial funding for the work; 3 = independent authors with minor declared industry ties, or a body whose work involves people with such ties; 4 = manufacturer-funded or manufacturer-authored. Credibility runs from A (highest) to D. Our sources cluster in the US, the UK and the Netherlands, with an Italian meta-analysis; most guideline-level and trial evidence comes from high-income academic hypertension and endocrine centres, and we found little from low-income countries.

What primary aldosteronism is

Aldosterone is a hormone made by the adrenal glands that tells the kidney to keep sodium and lose potassium. In PA one or both glands make too much of it, so blood pressure rises and potassium can fall (Sureshkumar 2026). MedlinePlus describes the usual cause as a benign adrenal growth making extra hormone, and adds that other conditions, such as kidney disease, liver cirrhosis, heart failure or dehydration, can raise aldosterone without it being PA (MedlinePlus). That second group is called secondary aldosteronism and is a different problem.

PA is usually split into one-sided (unilateral) and two-sided (bilateral) disease. Unilateral disease is the kind that surgery can cure; bilateral disease is treated with drugs. Rare inherited forms also exist (Sureshkumar 2026). PA is one of the causes covered in our guide to secondary hypertension.

Symptoms and red flags

Many people have no symptoms except high blood pressure. When the hormone excess is large, potassium can fall and cause muscle weakness, cramps or spasms, tiredness, headaches, irregular heartbeat, thirst and passing more urine (MedlinePlus). Red flags that should prompt a clinician to think of PA include blood pressure that does not improve with usual medicines, low potassium, and hypertension that begins young (MedlinePlus; Sureshkumar 2026). Atrial fibrillation without structural heart disease or an overactive thyroid is another reason to retest after a negative screen (Sureshkumar 2026); see atrial fibrillation.

Causes and risk factors

The immediate cause is autonomous aldosterone production by an adrenal adenoma or by overactive tissue in both glands. The 2016 guideline named the groups most worth testing: resistant or sustained hypertension, hypertension with low potassium, with an adrenal incidental nodule, with obstructive sleep apnoea, with a family history of early-onset hypertension or stroke, and first-degree relatives of someone with PA (Sureshkumar 2026, Table 1; Funder 2016). For the sleep link see obstructive sleep apnoea. We found no robust data on diet or lifestyle as causes of PA.

How common is it?

Published numbers disagree, and the reasons are mostly about who was tested and how.

• Higher estimates. In 1,015 adults at four US academic centres who all had a sodium suppression test, overt PA rose from about 11% with normal blood pressure to about 22% with stage 2 or resistant hypertension, and the ARR performed poorly at detecting it. The authors called PA a continuum rather than a rare category (Brown 2020). In the PATHWAY-2 substudy of 126 people with resistant hypertension, 10% to 38% met a PA-type definition depending on which cut-off was used (Williams 2018).
• Lower estimates. Dutch GPs screened 343 of 3,748 newly diagnosed, untreated patients; 9 of 74 with a suspicious screen were confirmed, giving 2.6% (95% CI 1.4 to 4.9) (Käyser 2018). The guideline's own evidence section used an estimated 2% to 6% before medicines in newly diagnosed hypertension (Adler 2025), while the Society's press release said 5% to 14% in primary care and up to 30% in referral centres (press release).
• The neutral view. A review of 39 studies (42,510 patients) found primary-care prevalence from 3.2% to 12.7% and referral-centre prevalence from 1% to 29.8%, with heterogeneity too high for a point estimate (Käyser 2016).

Our reading: PA is common enough that it is missed often, but "one in ten" is a headline from selected groups. In real-world care, testing is rare: 2.1% of 4,660 US adults with resistant hypertension were screened within two years (Jaffe 2020), and 1.6% of 269,010 veterans (Cohen 2021).

Testing and screening

The first test is a blood sample for aldosterone and renin, with potassium, from which the aldosterone-to-renin ratio (ARR) is calculated. The 2025 guideline suggests this for everyone with hypertension, with a conditional recommendation and low-certainty evidence. A positive screen needs suppressed renin and inappropriately high aldosterone. For immunoassay, the guideline's ARR cut-point is above 20 (ng/dL per ng/mL per hour) or above 70 (pmol/L per mU/L); mass-spectrometry cut-points are about 25% lower, and local laboratory cut-points should be used where possible (Adler 2025). A saline or other suppression test is suggested only for intermediate-probability cases where the patient wants surgery (Adler 2025). Screening can start without stopping most blood pressure drugs, though beta-blockers and some others can give misleading results (Sureshkumar 2026).

Is universal screening justified?

For: PA raises stroke, atrial fibrillation and heart-failure risk beyond ordinary hypertension (Monticone 2018), and nearly all tests in practice are missed (Jaffe 2020). Against: no trial shows that screening improves outcomes, the ARR has false positives, and health systems would struggle with volume. One 2026 editorial cites an estimate of 9.5 million US adults with PA among those with stage 2 hypertension, compared with about 1,180 hypertension specialists and 8,909 endocrinologists, and notes that the 2024 European and 2025 US hypertension guidelines still advise targeted screening (Thomas 2026; the author reports no relevant financial relationships). We have not independently confirmed the wording of those other guidelines.

Confirming the type: adrenal vein sampling and CT

If surgery is being considered, the guideline suggests adrenal CT and AVS, a catheter test that compares hormone levels from each adrenal vein. AVS may be skipped when a unilateral adenoma over 1.0 cm is very likely, such as in a person under 35 with marked PA and low potassium (Adler 2025). AVS is technically demanding and carries a risk of adrenal bleeding (Farah 2025).

The one randomised trial, SPARTACUS, compared CT-guided with AVS-guided treatment in 184 analysed people in the Netherlands and Poland. After 1 year, median drug doses were identical (3.0, p=0.52), blood pressure targets were reached by 42% versus 45% (p=0.82), biochemical cure after adrenalectomy was 80% versus 89% (p=0.25), and AVS added 2,285 euros per patient with under a 0.2 probability of being cost-effective at 30,000 euros per QALY (Dekkers 2016). The trial was not powered for long-term outcomes, and it did not compare surgery with spironolactone. The supporting review reports that AVS, compared with CT alone, may improve post-operative biochemical cure but increases the risk of adrenal haemorrhage (Farah 2025).

Treatments that work, with evidence

Surgery versus spironolactone

The question patients most want answered is the hardest. The guideline's systematic review pooled observational studies that compared medical therapy (mostly MRAs) with surgery. Medical therapy had higher all-cause death (OR 2.30, 95% CI 1.37 to 3.88, 6 studies), heart failure (OR 1.98, 1.25 to 3.14) and stroke (OR 1.82, 1.14 to 2.90), all rated low certainty. Major adverse cardiovascular events did not differ clearly (OR 1.25, 0.86 to 1.82; very low certainty). The authors list likely distortions: low MRA doses, missed doses, and unequal disease severity between groups (Farah 2025).

The Boston cohort adds a clue. Among 602 MRA-treated people, excess risk was concentrated in those whose renin stayed suppressed (cardiovascular HR 2.83, mortality HR 1.79); those with unsuppressed renin on higher doses showed no clear excess (Hundemer 2018). That suggests under-treatment, not drugs as such, may explain some of the gap, but it is an association only. Surgery is not risk-free and does not always normalise blood pressure, so the guideline leaves the choice to patients with lateralised disease (Adler 2025). For the drug side, see our spironolactone and eplerenone guide (we will link it here once it is live).

Medicines

Spironolactone is usually first-line for its effect and low cost. The Cleveland Clinic summary of the guideline reports starting doses of 12.5 to 25 mg a day, adjusted to blood pressure, potassium and renin. Eplerenone causes fewer hormonal effects but costs more and is usually taken twice daily (Sureshkumar 2026; these are guideline-practice doses, not advice). In the supporting review, spironolactone may control low potassium better than eplerenone with fewer drugs (Farah 2025). MRAs also alter other tests, which is why the guideline's pre-test advice lists them among medicines to stop for some screening protocols (Adler 2025). The wider resistant-hypertension evidence for spironolactone is strong (PATHWAY-2); see resistant hypertension and blood pressure medicines.

Supplements and lifestyle claims

We found no randomised trial of any supplement, herb, diet or lifestyle programme as a treatment for PA, so claims that a product "balances aldosterone" are Insufficient. Two safety points are documented: potassium supplements and potassium-containing salt substitutes are listed cautions with spironolactone, as are anti-inflammatory painkillers such as ibuprofen and naproxen (MedlinePlus). See also supplements and heart medicines and blood pressure prevention. Treating sleep apnoea may matter for blood pressure generally, but we found no data on its effect on PA specifically.

Risks and side effects

• Hormone effects of spironolactone: breast tenderness or enlargement, voice and hair changes and sexual side effects (MedlinePlus); menstrual irregularities (Sureshkumar 2026).
• Pregnancy and breastfeeding: MedlinePlus advises telling a doctor before use if pregnant, planning pregnancy or breastfeeding (MedlinePlus).
• AVS: increased risk of adrenal haemorrhage (Farah 2025); in SPARTACUS, 12 serious events with AVS and 9 with CT, not significantly different (Dekkers 2016).
• Cortisol co-secretion: about 22% of people with PA may also make mild extra cortisol, which can complicate AVS and cause adrenal insufficiency after surgery, so the guideline suggests a dexamethasone test in people with adrenal adenomas (Sureshkumar 2026).
• False positives and over-testing: the panel chose a conditional recommendation partly because the screening test can produce false positives (press release).

Interactions: blood pressure drugs change test results, and MedlinePlus asks people to tell their doctor about eplerenone, potassium supplements and anti-inflammatory painkillers such as ibuprofen and naproxen (MedlinePlus). Kidney disease changes both testing and drug safety; see chronic kidney disease and the heart.

Who to see

Testing can start with a GP or primary-care clinician. A positive screen is usually referred to endocrinology, where suppression testing, imaging and AVS are done when appropriate; a nephrologist or hypertension specialist may also lead (Sureshkumar 2026). In US veterans, a first visit with a nephrologist or endocrinologist, rather than primary care, was linked to more testing (Cohen 2021). Surgery is done by an endocrine surgeon, and AVS by a trained interventional radiologist. Track home readings with a validated monitor; see home blood pressure monitoring and hypertension.

Follow the money: who makes it and who funded the evidence

Who profits from testing and treatment

• Assay makers. DiaSorin, whose registered company details are in Vercelli, Italy, sells the LIAISON Aldosterone and LIAISON Direct Renin assays and markets them together for calculating the ARR; its page says PA affects at least 10% of hypertensive patients and 25% in resistant hypertension (DiaSorin). A larger screened population means more tests sold. That is our inference; we found no sales figures. A panel member who spoke for DiaSorin was kept out of the related reviews, votes and drafting (guideline Appendix A).
• Drug developers. AstraZeneca, headquartered in Cambridge, UK, acquired baxdrostat when it bought CinCor Pharma in February 2023 and lists a PA trial among its studies (AstraZeneca). In its BaxHTN trial of 796 patients, the placebo-corrected fall in systolic pressure was 8.7 mm Hg (1 mg) and 9.8 mm Hg (2 mg), with potassium above 6.0 mmol/L in 2.3%, 3.0% and 0.4% of the 1 mg, 2 mg and placebo groups; the trial was funded by AstraZeneca and others (Flack 2025). The US Food and Drug Administration approved it as an add-on for hypertension in 2026 (ACC).
• Generic MRAs. Spironolactone is described as low-cost, eplerenone as more expensive (Sureshkumar 2026). Cheap generics give few companies an incentive to fund large trials, which helps explain why surgery-versus-drug trials are missing; that is our inference.
• Clinical services. Hospitals and specialists gain referrals from wider screening. We have no documented figures on this.

Who funded the guidelines and trials

• 2025 guideline. Funding was provided by the Endocrine Society (Adler 2025), and the Society says it does not solicit or accept corporate support for guidelines. Co-sponsors were the American Association of Clinical Endocrinology, American Heart Association, European Society of Endocrinology, European Society of Hypertension, International Society of Hypertension and the Primary Aldosteronism Foundation (press release). We could not find how the Foundation is funded (its site links to sponsor pages we could not read). The Society itself is a Washington, DC, membership body; we did not find a breakdown of its revenue by source.
• Panel conflicts. Appendix A reports a 13-member panel with 31% carrying relevant or potentially relevant conflicts, and describes how they were managed: one member who spoke for DiaSorin did not vote on or draft related sections; one with an advisory role at Mineralys Therapeutics (developing an aldosterone synthase inhibitor) divested it before the guideline began and was excluded from the related reviews and votes on drug treatment; one with Bayer and AstraZeneca consulting relationships did not vote on directly related matters. Two earlier members, one with Daiichi Sankyo and Pfizer ties and one with Mineralys and AstraZeneca ties, left in July 2023 before recommendations were developed (Appendix A). A panel member, Dr Correa, also co-wrote the Cleveland Clinic summary and declared consulting and speaking for Amryt, Ascendis, Moderna, Novo Nordisk and Recordati (Sureshkumar 2026).
• 2016 guideline. The task force stated it received no corporate funding or remuneration (Funder 2016).
• Prevalence, cohort and cost studies. Brown: NHLBI and NIDDK (Brown 2020). Hundemer: NIH and the Doris Duke Charitable Foundation (Hundemer 2018). Jaffe: NIDDK and NCATS (Jaffe 2020). Cohen: NHLBI and NIDDK (Cohen 2021).
• Trials. PATHWAY-2: British Heart Foundation and NIHR, with MRC grants listed (PATHWAY-2). Mechanism substudies: British Heart Foundation and NIHR; authors declared lecture or consulting fees from several drug companies, among them Novartis, Amgen, Menarini, AstraZeneca, Merck Sharp & Dohme and GSK (Williams 2018). SPARTACUS: ZonMw and the Institute of Cardiology, Warsaw (Dekkers 2016).

Triangulation and documented integrity events

Two sources with opposite interests agree on something useful: the assay maker and the Society both stress that PA is under-diagnosed, and independent cohorts of real-world testing confirm very low testing rates (Jaffe 2020; Cohen 2021). They disagree on how often the disease exists, and the two lowest and highest figures come from different countries and designs. We found no regulatory ban, warning letter, recall or lawsuit tied to the aldosterone or renin assays in our searches, but that is an absence of results, not a clean bill of health. Most evidence comes from the US, the UK and the Netherlands.

Related research

For wider, evidence-graded context, see these Pure City Research guides:

• Hypertension
• Resistant hypertension
• Secondary hypertension
• Blood pressure medicines
• Home blood pressure monitoring
• Obstructive sleep apnoea
• Atrial fibrillation
• Chronic kidney disease and the heart
• Hypertensive emergency
• Supplements and heart medicines

Frequently asked questions

Sources and funding notes

What we could not verify. We could not open the full conflict-of-interest statements for Brown 2020, Käyser 2018, Käyser 2016 or SPARTACUS, and no funding statement appeared in the Käyser records. We did not open the NICE hypertension guideline (the page refused access), so UK guidance on PA is not covered. The 2024 European and 2025 US hypertension guideline positions are taken from one editorial, not the guidelines themselves. We could not read how the Primary Aldosteronism Foundation is funded, nor the Endocrine Society's revenue breakdown. We found no PA-specific results for baxdrostat, and no trial of supplements or diet in PA. Prevalence figures cannot be reconciled because designs differ.

1. Adler GK et al. Primary aldosteronism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2025 (full text) — guideline; funded by the Endocrine Society; 31% of the panel with relevant or potential conflicts.
2. Farah MH et al. Systematic review supporting the Endocrine Society guideline. J Clin Endocrinol Metab 2025 (full text) — systematic review; partly funded by the Endocrine Society.
3. Endocrine Society. Guideline press release (2025) — society statement on funding and co-sponsors.
4. Endocrine Society. Primary aldosteronism guideline page — panel and co-sponsor list.
5. Funder JW et al. Endocrine Society guideline 2016 — no corporate funding stated.
6. Sureshkumar NB et al. Interpreting the 2025 Endocrine Society guideline. Cleve Clin J Med 2026 — US; commentary; one panel member among authors; declared consulting for Amryt, Ascendis, Moderna, Novo Nordisk, Recordati.
7. Thomas G. New guidance on primary aldosteronism: rethinking screening. Cleve Clin J Med 2026 — US; editorial; no relevant financial relationships.
8. Brown JM et al. The unrecognized prevalence of primary aldosteronism. Ann Intern Med 2020 — US; NHLBI and NIDDK; conflicts not verified.
9. Käyser SC et al. Prevalence of primary aldosteronism in primary care. Br J Gen Pract 2018 — Netherlands; no funding statement found.
10. Käyser SC et al. Study heterogeneity and estimation of prevalence of primary aldosteronism. J Clin Endocrinol Metab 2016 — Netherlands and Germany; no funding listed in the record.
11. Williams B et al. PATHWAY-2. Lancet 2015 — UK; British Heart Foundation, NIHR, MRC grants.
12. Williams B et al. PATHWAY-2 mechanisms substudies. Lancet Diabetes Endocrinol 2018 (full text) — UK; British Heart Foundation and NIHR; declared pharmaceutical ties among authors.
13. Dekkers T et al. SPARTACUS. Lancet Diabetes Endocrinol 2016 — Netherlands and Poland; ZonMw and the Institute of Cardiology, Warsaw.
14. Monticone S et al. Cardiovascular events and target organ damage in primary aldosteronism. Lancet Diabetes Endocrinol 2018 — Italy; funding listed as none.
15. Hundemer GL et al. Cardiometabolic outcomes and mortality in medically treated primary aldosteronism. Lancet Diabetes Endocrinol 2018 — US; NIH and Doris Duke Charitable Foundation; no competing interests.
16. Cohen JB et al. Testing for primary aldosteronism and MRA use among US veterans. Ann Intern Med 2021 — US; NHLBI and NIDDK grants.
17. Jaffe G et al. Screening rates for primary aldosteronism in resistant hypertension. Hypertension 2020 — US; NIDDK and NCATS grants.
18. Flack JM et al. Baxdrostat in uncontrolled and resistant hypertension (BaxHTN). N Engl J Med 2025 — funded by AstraZeneca and others; industry-funded.
19. AstraZeneca. BaxHTN press release (2025) — UK company; seller; manufacturer statement.
20. American College of Cardiology. FDA approves baxdrostat (19 May 2026) — US professional society news.
21. DiaSorin. Hypertension testing page — Italian company; assay seller.
22. MedlinePlus. Aldosterone test — US National Library of Medicine.
23. MedlinePlus. Spironolactone — US National Library of Medicine.
24. Primary Aldosteronism Foundation — US patient organisation; co-sponsor of the guideline; funding not found.

Educational research reviewed 6 October 2026. This article is not medical advice; talk to a qualified clinician or pharmacist before starting, stopping or combining treatments.