Conn's syndrome

• Hyperaldosteronism - primary and secondary
• Primary: adrenal cortex hyperplasia, adenoma (intrinsic)
• Secondary - renal artery stenosis, heart failure, liver cirrhosis (elsewhere in the body)

Via the RAAS - renal retion of H2O and Na+ so high blood pressure, headache and electrolyte disturbance symptoms - muscle spasms, cardiac arrhythmias

Hypokalaemia coupled with hypertension is suggestive of primary hyperaldosteronism 

The first line investigation for this is a plasma aldosterone/renin ratio, which should show high aldosterone levels alongside low renin levels.