Essential hypertension
Investigations
1st investigations to order
urinary albumin-to-creatinine ratio (UACR)
Test
UACR is useful for evaluation of chronic kidney disease (CKD).[2][64] Increased albumin excretion suggests end-organ damage.
This test is recommended for all patients with newly diagnosed hypertension.[1] For patients with moderate-to-severe CKD, it is recommended to repeat serum creatinine, eGFR, and UACR at least annually to monitor disease progression.[1]
Result
proteinuria
ECG
Test
May reveal changes suggestive of comorbid chronic coronary disease; however, a normal result does not rule coronary disease out.
Result
may show evidence of left ventricular hypertrophy or old infarction
fasting metabolic panel with estimated GFR
Test
Risk of hypertension is increased if there are features of metabolic syndrome (abdominal obesity, dyslipidaemia, hyperglycaemia).
Unprovoked hypokalaemia suggests hyperaldosteronism.
GFR is calculated according to the Modification of Diet in Renal Disease (MDRD) formula or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation (formulas available with and without cystatin).[76] [ 2021 race-free CKD-EPI equations for glomerular filtration rate (GFR) Opens in new window ] [ Glomerular Filtration Rate Estimate by the IDMS-Traceable MDRD Study Equation Opens in new window ]
Result
may show renal insufficiency, hyperglycaemia, hypokalaemia, hyperuricaemia, or hypercalcaemia
lipid panel
Test
Hypertension often co-exists with dyslipidaemia. Risk of hypertension is increased in the presence of dyslipidaemia and abdominal obesity.
Result
may show high LDL, low HDL, or high triglycerides
urinalysis
Test
Routine test to screen for secondary causes of hypertension.
Presence of haematuria suggests underlying renal disease.
Result
may show proteinuria or haematuria
haemoglobin
Test
Anaemia is associated with chronic renal failure.
Polycythaemia may be seen with phaeochromocytoma.
Result
anaemia or polycythaemia suggests secondary cause or complication
thyroid-stimulating hormone
Test
Indicated if signs/symptoms of hypo- or hyperthyroidism.
Result
high or low if thyroid dysfunction
Investigations to consider
plasma renin activity
Test
Indicated when unprovoked hypokalaemia present.
The 2024 ESC guidelines recommend that screening for primary aldosteronism by renin and aldosterone measurements should be considered in all adults with confirmed hypertension (BP ≥140/90 mmHg).[1]
Result
low renin suggests hyperaldosteronism
plasma aldosterone
Test
Indicated in the following situations: BP is sustained above 150/100 mmHg on 3 measurements over different days, with hypertension resistant to 3 conventional antihypertensive drugs (including a diuretic), or controlled BP (140/90 mmHg) on 4 or more antihypertensive drugs; hypertension and spontaneous or diuretic-induced hypokalaemia; hypertension and adrenal incidentaloma; hypertension and sleep apnoea; hypertension and a family history of early-onset hypertension or cerebrovascular accident at a young age (40 years); hypertensive first-degree relatives of patients with primary aldosteronism.[75] The 2024 ESC guidelines recommend that screening for primary aldosteronism by renin and aldosterone measurements should be considered in all adults with confirmed hypertension (BP ≥140/90 mmHg).[1]
Result
high aldosterone or failure to suppress with salt loading suggests hyperaldosteronism
renal duplex ultrasound/MRA renal arteries/CT angiography
Test
Indicated in young patients (age <40 years) with severe hypertension or renal artery bruits.
Ultrasound provides haemodynamic information and magnetic resonance angiogram (MRA) provides anatomical information, in lieu of renal angiogram. CT angiography is accurate in atherosclerotic disease.
Result
may show renal artery stenosis, renal scarring, or lesions
24-hour urine phaeochromocytoma screen
Test
Indicated with symptoms/signs of catecholamine excess.
Result
elevated catecholamines if phaeochromocytoma
plasma fractionated metanephrines
Test
Indicated with signs/symptoms of catecholamine excess. This test is easier to perform than 24-hour urine screen, but has a higher rate of false positives.
Result
elevated metanephrines if phaeochromocytoma
24-hour urine free cortisol
Test
Indicated when stigmata of Cushing's disease present.
Result
elevated in Cushing's disease
sleep study
Test
Sleep study may be considered in cases of resistant hypertension and also for patients with signs or symptoms of obstructive sleep apnoea.[47]
Result
may show results consistent with obstructive sleep apnoea
echocardiography
Test
Assesses left ventricular hypertrophy and left ventricular function.
Echocardiogram may have prognostic implications, but is not routinely recommended except as recommended by guidelines.[2][77]
There was increased risk of mortality and cardiovascular events in patients with increased left ventricular mass and abnormal geometric left ventricular hypertrophy on echocardiogram.[72][73]
Result
increased left ventricular mass, decreased left ventricular systolic function, impaired left ventricular diastolic function, and increased left atrial size and decreased function
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