Primary aldosteronism: screening, confirmatory testing and targeted treatment

Clinical scope and immediate priorities

Primary aldosteronism is a common and underdiagnosed cause of secondary hypertension associated with excess cardiovascular and kidney risk beyond blood pressure alone. Contemporary guidance supports a lower threshold for screening, especially when hypertension is resistant, severe or accompanied by hypokalaemia. Endocrine disorders commonly evolve over weeks or months but can decompensate acutely. Management should distinguish biochemical diagnosis from clinical severity, identify medicines or intercurrent illness that alter physiology, and avoid treating a laboratory value without understanding the patient context. Education and self-management are central to long-term outcomes.

Recognition and differential diagnosis

Clues include resistant hypertension, spontaneous or diuretic-induced hypokalaemia, adrenal incidentaloma, sleep apnoea and early-onset hypertension or stroke. Normal potassium does not exclude primary aldosteronism, so screening should not be limited to hypokalaemic patients. The practical aim is to identify features that change urgency, distinguish common mimics and avoid anchoring on a single test result. Where the presentation is atypical, reassess the working diagnosis rather than forcing the findings to fit it.

Assessment and investigations

Screen with aldosterone and renin interpreted as a ratio or paired values according to the local laboratory method. Medication effects, sodium intake and potassium status can alter results, so preparation matters. Confirmatory suppression testing is used selectively. Adrenal CT evaluates anatomy, but adrenal venous sampling is usually required before surgery to establish unilateral secretion in most adults. Investigations should be sequenced so that urgent bedside information is obtained first, followed by tests that refine cause, severity or treatment choice. Trends, prior results and treatment effects often matter more than whether one value sits just inside or outside a reference range.

Initial and definitive management

Unilateral aldosterone-producing disease can be treated with adrenalectomy when appropriate. Bilateral disease or patients not undergoing surgery are treated with mineralocorticoid receptor antagonists, titrated to blood pressure, potassium and renin response where used. Address overall cardiovascular risk rather than focusing only on potassium normalisation. Treatment should address reversible causes and immediate physiological risk while preserving options for definitive care. Medication selection requires attention to allergies, interactions, renal or hepatic function, pregnancy where relevant, and the possibility that a medicine suitable in one health system may not be first-line in another.

Escalation, complications and special situations

Severe hypokalaemia, uncontrolled hypertension or adrenal mass features concerning for malignancy requires expedited specialist assessment. Pregnancy changes both testing and treatment options and requires expert management. Escalate early when instability, organ dysfunction, rapidly progressive symptoms or a high-risk comorbidity is present. Frailty, pregnancy, immunosuppression, extremes of age and major renal or hepatic impairment can alter both presentation and treatment tolerance, so protocol-based care still requires individualisation.

International practice across English-speaking health systems

Across the United Kingdom, United States, Canada, Australia, New Zealand and Ireland, the core clinical principles are broadly similar, but drug licensing, formularies, emergency pathways, screening thresholds, referral criteria and professional scope can differ. Use the most recent national or regional guidance, local antimicrobial or medicines policy, and the relevant product information when an operational detail could change treatment. MDPDA therefore presents a common evidence-based framework and highlights areas that should be adapted locally rather than implying that one country’s pathway is universal.

Monitoring, follow-up and prevention

Follow-up should be purposeful rather than routine. Define what is being monitored, when it should be reassessed and what finding would change management. Review adherence and adverse effects, repeat objective measurements when they inform risk, and reconsider the diagnosis if the clinical course is inconsistent with expectations. Safety-netting should state which symptoms require urgent reassessment and which service should be contacted. For chronic disease, prevention, vaccination where relevant, smoking cessation, nutrition, physical activity and management of related cardiovascular or metabolic risk can be as important as disease-specific treatment. After surgery, monitor potassium, renal function and blood pressure because antihypertensive requirements can fall rapidly. On medical therapy, monitor potassium and kidney function after dose changes.

Common pitfalls and safety checks

Normal potassium does not exclude primary aldosteronism. An adrenal nodule on CT does not prove that it is the source of aldosterone excess. Medication effects can distort screening tests. Treat cardiovascular risk, not just the laboratory abnormality. A useful final check is to ask what dangerous alternative diagnosis could still explain the presentation, whether the patient has demonstrated an appropriate response to treatment, and whether the discharge or transfer plan is safe if symptoms recur.

Documentation, communication and shared decisions

Documentation should make the clinical reasoning visible. Record the key positive and negative findings, relevant risk stratification, important investigations, treatment rationale, discussions with the patient or family where appropriate, and the trigger for escalation or review. When care crosses settings, handover should identify unresolved diagnostic questions, medicines started or withheld, pending results and who is responsible for follow-up. Shared decisions are particularly important when more than one reasonable strategy exists or when treatment benefit must be balanced against bleeding, frailty, treatment burden or quality of life.

Implementation across care settings

Implementation should include medicines access, self-monitoring capability, sick-day education and the patient’s ability to recognise deterioration. Nurses, pharmacists, dietitians and primary-care clinicians often carry much of the longitudinal management, so targets and escalation thresholds should be communicated clearly. Laboratory monitoring should have an owner and an interval linked to the treatment decision. When recommendations differ among national diabetes or endocrine organisations, adapt the operational target to comorbidity, pregnancy, frailty and local medicine availability rather than pursuing a number in isolation.

Quality and patient-safety review

Before closing the episode of care, confirm that the working diagnosis remains consistent with the observed course, that high-risk alternatives have been considered, and that treatment has not introduced a new avoidable hazard. Review allergies, interactions, renal or hepatic constraints, pregnancy considerations where relevant, and the patient’s ability to follow the plan. The safest pathway is one in which the next clinician can understand what has been decided, what remains uncertain and which finding should trigger escalation.

Applying evidence to the individual patient

Guidelines provide a framework, but safe implementation depends on the patient’s baseline function, comorbidities, concurrent medicines, treatment goals and access to follow-up. Recommendations should be interpreted in light of absolute rather than relative benefit where possible, and clinicians should identify when the evidence base under-represents older people, pregnancy, severe kidney or liver impairment, multimorbidity or other groups. When two reasonable options exist, explain the trade-offs and document the reason for the selected approach. If local policy differs from an international recommendation, determine whether this reflects formulary, service configuration, licensing or genuinely different evidence. Reassessment is part of evidence-based care: a working diagnosis or treatment plan that no longer fits the clinical course should be revised rather than defended simply because it matched the initial pathway.

Practical review checklist

Before finalising management, confirm that the severity has been classified correctly, essential investigations have been acted on, and any test still pending has a named clinician or service responsible for review. Reconcile regular medicines and temporary changes, check whether monitoring is required after initiation or dose adjustment, and make the follow-up interval proportionate to risk. Explain the plan in language the patient can use, including what improvement is expected, which adverse effects matter and which symptoms require urgent help. Where care is shared between primary, secondary, dental, pharmacy or community services, avoid ambiguous instructions such as ‘follow up as needed’; specify who should do what and when. This final systems check often prevents harm that is not caused by the clinical decision itself but by gaps in implementation.