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Conn's Syndrome
Conn's Syndrome: when aldosterone turns the volume up on salt retention
Clinical review September 2026
The hormone behind a kind of high blood pressure
Conn’s syndrome is the older name for primary aldosteronism. In this condition, one or both adrenal glands make aldosterone more independently than they should. Aldosterone tells the kidneys to retain sodium and water and pass more potassium into urine; in excess it can raise blood pressure and sometimes lower potassium.
Many people feel no different from someone with ordinary high blood pressure. Others may have headaches, muscle weakness, cramps or palpitations, but symptoms do not make the diagnosis. A normal potassium result does not rule it out either.
Screening asks two hormones a question
The first test usually measures aldosterone and renin, then considers their relationship alongside potassium and blood pressure. Preparation matters: posture, salt intake and several blood-pressure medicines can influence results. A positive screen may lead to confirmation testing and adrenal imaging, but a scan alone cannot reliably say which gland is making excess aldosterone.
When surgery is an option, adrenal vein sampling may be used to compare hormone output from each gland. It sounds intricate because it is; it answers a genuinely important question—would removing one adrenal gland be expected to help?
Treatment follows the source
If excess production is clearly from one side, adrenal surgery may be considered. If it comes from both glands, or surgery is not suitable, medicines that block aldosterone’s action such as spironolactone or eplerenone are commonly used. Monitoring blood pressure, potassium and kidney function keeps the plan safe. The aim is not simply a prettier blood-pressure number; it is reducing the effects of aldosterone excess on the heart and kidneys.
Important safety note
This page is general education, not personal medical advice. Seek urgent help for collapse, confusion, severe vomiting or diarrhoea with adrenal insufficiency, severe chest pain, severe breathlessness, new weakness or neurological symptoms, or acute severe illness. Follow individual instructions from your endocrine team for medicines and investigations.
Further reading
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