Blood glucose

Sodium, potassium and creatinine (check daily), low Na and K in hyperaldosteronism and renal artery stenosis

Plasma troponin, if acute coronary syndrome suspected

Full blood count

Plasma renin/aldosterone (for later analysis)

Urine stick test and microscopy (renal impairment with minimal proteinuria suggests renal artery stenosis)

Ultrasonography of kidneys and urinary tract

Urinary catecholamine excretion

Urinary free cortisol excretion if suspected Cushing syndrome (Table 55.6)

Chest X-ray

ECG

Computed tomography (CT) or
magnetic resonance imaging (MRI) of the brain, if there are neurological symptoms, headache, nausea and vomiting, or retinal haemorrhages, exudates or papilloedema

Contrast enhanced CT of the chest, if aortic dissection is suspected