Table 2 –
Diagnostics of secondary hypertension
| Possible causes | Clinical indications | Diagnostics | |||
|---|---|---|---|---|---|
| Clinical history | Physical examination | Laboratory investigations | First-line test(s) | Additional confirmatory test(s) | |
| Common causes | |||||
| Renal parenchymal disease | ● History of urinary tract infection or obstruction, haematuria (blood in the urine), analgesic abuse ● family history of polycystic kidney disease |
Abdominal masses (in case of polycystic kidney disease) | ● Presence of protein, erythrocytes, or leucocytes in the urine ● decreased GFR |
Renal ultrasound | Detailed work-up for kidney disease |
| Renal artery stenosis | ● Fibromuscular dysplasia: early onset hypertension (especially in women). ● Atherosclerotic stenosis: hypertension of abrupt onset, worsening or increasingly difficult to treat; flash pulmonary oedema |
Abdominal bruit (abnormal sound) | ● Difference of >1.5 cm in length between the two kidneys (renal ultrasound), ● rapid deterioration in renal function (spontaneous or in response to RAA blockers) |
Renal Duplex Doppler ultrasonography | ● Magnetic resonance angiography, ● spiral computed tomography ● intra-arterial digital subtraction angiography |
| Primary aldosteronism | ● Muscle weakness ● family history of early onset hypertension and cerebrovascular events at <40 years of age |
Arrhythmias (in case of severe hypokalaemia) | ● Hypokalaemia (spontaneous or diuretic-induced) ● incidental discovery of adrenal masses |
Aldosterone–renin ratio under standardized conditions (corrected hypokalaemia and withdrawal of drugs affecting RAA system) | ● Confirmatory tests (oral sodium loading, saline infusion, fludrocortisone suppression, or captopril test) ● adrenal CT scan ● adrenal vein sampling |
| Uncommon causes | |||||
| Pheochromocytoma | ● Paroxysmal hypertension or a crisis superimposed to sustained hypertension; ● headache, sweating, palpitations and pallor; ● positive family history of pheochromocytoma |
Skin stigmata of neurofibromatosis (café-au-lait spots, neurofibromas) | Incidental discovery of adrenal (or in some cases, extra-adrenal) masses | Measurement of urinary fractionated metanephrines or plasma-free metanephrines | ● CT or MRI of the abdomen and pelvis; ● 123I-labelled meta-iodobenzyl-guanidine scanning; ● genetic screening for pathogenic mutations |
| Cushing syndrome | ● Rapid weight gain, ● polyuria (excessive production of urine), ● polydipsia (excessive thirst), ● psychological disturbances |
Typical body habitus (central obesity, moon-face, buffalo hump, red striae (stretch marks), hirsutism) | Hyperglycaemia | 24-h urinary cortisol excretion | Dexamethasone-suppression test |
CT, computed tomography; GFR, glomerular filtration rate; MRI, magnetic resonance imaging; RAA, renin–angiotensin–aldosterone
Modified from Ref77.