Table 10 Clinical clues and diagnostic tests of secondary hypertension

Parenchymal renal diseases

Urinary tract infection or obstruction, analgesic abuse, familial history of polycystic kidney disease

Abdominal mass (polycystic kidney disease)

Proteinuria, hematuria, pyuria, reduced glomerular filtration rate

Renal US

Further studies for kidney diseases

Renal artery stenosis

Fibromuscular dysplasia, premature hypertension (female), atherosclerotic diseases, sudden onset or worsening of hypertension, resistant hypertension, recurrent pulmonary edema

Abdominal bruit

Rapid worsening of renal function (spontaneous or after ACE inhibitor or ARB treatment)

Kidney size difference >1.5 cm, duplex Doppler US, CT

Magnetic resonance imaging, digital subtraction angiography

Primary aldosteronism

Muscle weakness, premature hypertension, familial history of premature stroke (<40 years old)

Arrhythmia (severe hypokalemia)

Hyperkalemia (spontaneously or after treatment by ACE inhibitor or ARB), incidental adrenal mass

Aldosterone renin ratio (after correction of hypokalemia and disappeared effect of ACE inhibitor or ARB)

Suppression test by saline infusion, fludrocortisone, and/or captopril, adrenal CT, adrenal vein sampling

Pheochromo-cytoma

Paroxysmal hypertension, emergency visit by persistent hypertension with headache, sweat, and/or pallor, familial history

Café-au-lait lesion and neurofibro-matosis neurofibroma

Incidental adrenal mass (extraadrenal mass in some cases)

Metanephrine and/or nor-metanephrine in 24-h urine

Abdominal and/or pelvic CT or magnetic resonance imaging, radioisotope scan using meta-iodobenzyl-guanidine

Cushing syndrome

Rapid weight gain, polyuria, polydipsia, psychiatric problems

Central obesity, mood face, buffalo hump, abdominal striae, hirsutism

Hyperglycemia

Cortisol in 24-h urine

Dexamethasone suppression test