<International Circulation>:What are the common causes of secondary hypertension that physicians mistakenly diagnose and how can physicians avoid that mistaken diagnosis?
　　Prof. Viera: The error to avoid， if one is to test for causes of secondary hypertension such as pheochromocytoma or renal vascular disease， is to make sure that the tests done are sensitive and specific enough and that they are done in the correct manner. For pheochromocytoma for example the testing for plasma metanephrines must be done according to a very standard protocol else you risk a false positive. A false positive could then lead to someone being labeled with having a pheochromocytoma when they really do not. It is not so much that the test is negative because if the test is negative it is probably good reassurance that they do not have pheochromocytoma. But if the test is positive and was performed incorrectly， that could be a false positive.

　　《国际循环》：临床医生误诊继发性高血压的常见原因是什么？临床医生如何避免误诊继发性高血压？
　　Viera教授：说到避免误诊继发性高血压，如果要检查继发性高血压原因（例如嗜络细胞瘤或肾血管疾病），要确保所采用的检测手段具有足够高的敏感性和特异性，同时是以正确的方式开展的。以嗜络细胞瘤为例，血浆肾上腺素的检测应当依据非常严格的标准，否则会得出假阳性结果。随后，假阳性结果可能使某些患者被诊断为嗜络细胞瘤，但是事实并非如此。如果检测结果是阴性的话，没什么太大问题，因为结果为阴性的话，可能确保了患者没有嗜络细胞瘤。但是，如果检测结果是阳性同时检测方法错误，可能得出的是假阳性结果。

　　<International Circulation>:What are the reasons that physicians might miss the diagnosis of secondary hypertension?
　　Prof. Viera: The two major times when a physician should reconsider their diagnosis are at the time of a new diagnosis of hypertension and when the patient’s hypertension has been difficult to control. The time that is probably more overlooked than the other is the new evaluation. Some people with hypertension may be assumed to have essential hypertension and not to have a secondary underlying cause and thus not have the complete new patient evaluation. The ways then to avoid missing secondary hypertension are to ensure a systematic approach to every newly diagnosed hypertensive patient. The history， exam and laboratories recommended for the new patient are partly designed to exclude secondary causes. And then secondarily， a patient who’s hypertension has been difficult to control， regardless of whether the initial evaluation led the clinician to make a diagnosis of or consider a diagnosis of secondary hypertension or not， if it is a resistant hypertension or very difficult to control on three or maybe more medications， it is at that time that the physician should reconsider secondary causes and in particular the most common secondary causes such as aldosteronism， which may be missed at the initial evaluation because not all aldosteronism presents with the classic low potassium level. Thirty percent of patients with aldosteronism actually have normal potassium levels and therefore it could be missed. The only clue is that you can’t get the blood pressure under control. I think that is the trick; to remember to consider it systematically at the new evaluation and to reconsider it in patients whose blood pressure is very difficult to control. Of course it should be considered in all children because 85% of children less than twelve years of age have a secondary cause although obesity is becoming more prevalent amongst children and essential hypertension (i.e. hypertension with no secondary cause) is also becoming more prevalent among children at least here in the United States.

　　《国际循环》：医生漏诊继发性高血压的可能原因是什么？
　　Viera教授：主要是在以下两种情形下医生应当重新思考自己作出的诊断，一种情形是在新诊断高血压时，另一种情形是在患者的血压难以控制时。两种情形中可能更易被忽视的是新诊断高血压时。一些高血压患者可能被医生认定为是原发性高血压，没有引起继发性高血压的潜在原因，因此对这些患者医生没有进行新诊断高血压患者的完整评估。因此，避免误诊继发性高血压的方法就是确保对每一位新诊断高血压患者都进行系统的评价。新发高血压患者的病史、体格检查和实验室检查的设计在某些方面是为了排除继发性高血压。另外，如果患者的血压难以控制时，无论初始评估使得临床医生是否诊断或考虑诊断为继发性高血压，若患者即使应用三种甚至更多种药物血压也难以控制，此时医生应当考虑患者存在引起继发性高血压的原因，尤其是醛固酮增多症这一导致继发性高血压最常见的病因，在初次评估时可能会漏掉醛固酮增多症，因为并不是所有的醛固酮增多症都会有经典的低血钾表现。实际上，30%的醛固酮增多症患者血钾水平正常，因此可能会被漏诊。此时唯一的线索就是血压难以控制。我想这就是窍门所在：记住在新诊断高血压患者时系统地考虑问题，另外对血压非常难以控制的患者重新考虑诊断。当然，在所有的儿童高血压患者都应当考虑醛固酮增多症。这是由于尽管儿童肥胖越来越常见，原发性高血压（即没有继发原因的高血压）在儿童中也变得越来越常见（至少在美国是如此），但是12岁以下儿童高血压患者仍有85%为继发性高血压。