Approach to a case of secondary hypertension

Secondary hypertension, i.e. where a definite cause for hypertension can be found, is not uncommon in clinical practice and accounts for about 5% cases of hypertension. Common causes of secondary hypertension include renal parenchymal disease, renovascular hypertension, Conn Syndrome and pheochromocytoma. In Asian countries, aortoarteritis is still a common cause of secondary hypertension among young patients, especially females. Early diagnosis and appropriate treatment may significantly alter the natural history of the disease with substantial improvement in prognosis. Whenever a patient is diagnosed with hypertension, every effort should be made to rule out any possible secondary cause for the hypertension. Suspicion of secondary hypertension should be high in early or late onset hypertension, resistant hypertension, accelerated hypertension and in patients with markedly elevated blood pressure with severe target organ damage. Reno-vascular hypertension can be evaluated by non-invasive modalities like Ultrasound Doppler, MR angiography and CT angiography. If primary aldosteronism is suspected, patients should undergo screening with plasma rennin/aldosterone ratio and MRI for the detection of morphological adrenal abnormalities. Patient suspected of pheochromocytoma shows an increase in plasma or urinary catecholamines, but CT and MRI are needed to localize the tumours. Targeted testing should be done in all these patients to rule out any possible cause for secondary hypertension. Careful and thorough clinical evaluation and simple algorithms are needed to avoid unnecessary tests in making the diagnosis of secondary forms of hypertensions more accurately and promptly. Correcting the cause of secondary hypertension can lead to cure, avoiding the need for long-term medical therapy.