Resistant Hypertension - Definition, Diagnosis, and Treatment

Aneroid sphygmomanometer (blood pressure gauge)
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Resistant hypertension is high blood pressure that does not respond to treatment. Specifically, resistant hypertension is defined as blood pressure that remains elevated above treatment goals despite administration of an optimal three-drug regimen that includes a diuretic. Because some cases of high blood pressure are difficult to treat, and may require a combination of multiple drugs before control is established, high blood pressure cannot be called “resistant” until this three-drug combination therapy has failed.

How is Resistant Hypertension Diagnosed?

Resistant hypertension is diagnosed when the blood pressure continues to be elevated despite trying combination therapy with three drugs. The standard guidelines state that:

What Causes Resistant Hypertension?

There are many things that can cause resistant hypertension, and proper medical testing is required to investigate each of these potential causes. The three most common causes of resistant hypertension are:

  • Patient noncompliance with treatment
  • Secondary hypertension (Usually from overactive adrenal glands)
  • Fluid retention (usually expansion from kidney failure)

Additionally, it is important to make sure that what appears to be resistant hypertension isn’t actually pseudohypertension or white coat hypertension.

The most common cause of resistant hypertension and the most difficult to treat is what medical researchers commonly refer to as "patient noncompliance." The term "patient noncompliance" refers to instances where patients are not adherent to the prescribed treatment but is not meant to imply the patient is always to blame.

To the contrary, most cases of "noncompliance" actually indicate that circumstances not in the patient's control have made following the recommended therapy either impractical or intolerable.

For example, patients are sometimes placed in situations where the recommended medication is too expensive or the pharmacy is very far away, or doctor appointments are difficult to keep. More commonly, prescribed medications may have side effects, like a headache or upset stomach, of sufficient strength that the patient will stop taking the prescribed medicine to avoid suffering them. When side effects occur, the doctor usually changes to a medicine that is better tolerated. But what happens if you've tried all the different medicines and the only one that works is the one that gives you the worst upset stomach? Clearly, situations like this require a great deal of thoughtful problem solving.

What is the Treatment for Resistant Hypertension?

Because resistant hypertension is usually the result of some underlying issue, treatment focuses on correcting this underlying issue.

For example, in cases where the resistant hypertension is caused by patient noncompliance, doctors will work with the patient to determine the root cause of the noncompliance and to alleviate it. In situations where the body fluid balance is abnormal, usually as a result of kidney disease, measures such as dialysis might be necessary. If a hormone imbalance is the cause of resistant hypertension, then treatment efforts are focused on correcting the patient’s hormone profile.

Learn More:

1. Nuesch, R., et al. Relation Between Insufficient Response to Antihypertensive Treatment and Poor Compliance with Treatment: A Prospective Case-Control Study. British Medical Journal, 323(7305): 142-6.
2. Graves, JW. Management of Difficult to Control Hypertension. Mayo Clinic Proceedings, 75(3): 278-84.
3. Yakovlevitch, M., Black, H.R. Resistant Hypertension in a Tertiary Care Clinic. Archives of Internal Medicine, 151(9): 1786-92.
4. Setaro, JF., Black, H.R. Refractory Hypertension. New England Journal of Medicine, 327(8): 543-7.

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