Online Health Chat with George Thomas, MD

May 22, 2013


According to the American Heart Association, 77.9 million Americans—one out of three people—have been diagnosed with high blood pressure. Although about 50 percent of the population can control high blood pressure, uncontrolled hypertension can cause irreversible kidney damage. It is the second leading cause of chronic kidney disease in the United States.

If lifestyle changes, which include quitting smoking, losing weight, eating a low salt diet, exercising and relieving stress in your life, and multiple blood pressure medications cannot successfully lower your blood pressure, this results in resistant hypertension. In addition to chronic kidney disease, uncontrolled hypertension can increase the risk of heart disease and stroke. Other medical conditions are often associated with high blood pressure as well, such as diabetes.

Prevention and early treatment are keys to preventing the potentially serious consequences of hypertension.

About the Speaker

George Thomas, MD is a staff physician in the Department of Nephrology and Hypertension for the Glickman Urological & Kidney Institute at Cleveland Clinic.

He is board certified in internal medicine – nephrology, and completed a fellowship in nephrology and hypertension at Cleveland Clinic. Dr. Thomas completed his residency in internal medicine at Tufts University-St. Elizabeth’s Medical Center, in Boston, after completing medical school at Bharati Vidyapeeth’s Deemed University Medical College in Pune, India. Dr. Thomas has also completed a graduate program in public health at Johns Hopkins School of Hygiene & Public Health, in Baltimore. Dr. Thomas’ specialty interests include chronic kidney disease, hypertension, resistant hypertension, end-stage renal disease, glomerular disease, adrenal diseases, dialysis, hemodialysis and kidney stones.

Let’s Chat About Resistant Hypertension: Get Your Questions Answered

Moderator: Welcome to our ‘Resistant Hypertension’ online health chat with George Thomas, MD. We are very excited to have him here today! Let's begin with some general information while Dr. Thomas begins answering your questions.

Resistant Hypertension Diagnosis

re-wired: If resistant hypertension is misdiagnosed, what does that mean to the patient?

George_Thomas,_MD: Blood pressure should be correctly measured to establish a diagnosis of hypertension. Some patients have what is called ‘white coat hypertension’, i.e. elevated blood pressure in the doctor's office and normal blood pressures at home. Diagnosis for this condition involves checking home blood pressures or using a 24-hour ambulatory blood pressure monitor (which automatically checks blood pressures for 24 hours). Patients may end up taking multiple blood pressure medications if hypertension is misdiagnosed. The downside would be that the blood pressure could drop very low, which would lead to symptoms of dizziness, lightheaded sensations, etc. as blood flow to various organs may be affected.

rich dude: Does primary or secondary hypertension become resistant hypertension? Is it usually one or the other, or can it be either?

George_Thomas,_MD: It can be either—the difference between primary and secondary hypertension is that in the former (primary), no specific cause can be identified whereas in secondary hypertension, there is a hormonal or vascular cause usually contributing to the high blood pressures. Treatment of these causes could lead to better control of blood pressures. Patients with resistant hypertension should be investigated for secondary causes.

no problem: What characteristics make a person more susceptible to chronic hypertension than others?

George_Thomas,_MD: Age, race, family history, being overweight, excessive salt (sodium) consumption, and daily alcohol intake of more than two drinks in men and one drink in women are factors that contribute to hypertension.

One in three Americans has high blood pressure. More than half of these cases are not under control. Hypertension is a silent killer and you may not experience any symptoms until organ damage occurs. It is critical to have your blood pressure checked with your doctor and begin a treatment regimen if your doctor advised you to do so. Medications should not be stopped without consulting your doctor. If you have side effects, discuss them with your doctor for potential alternatives.

Salt or sodium intake plays a big role—more than most people realize—in sustaining hypertension. Remember that it is not just adding salt at the table, sodium also comes from packages and processed foods. And food does not necessarily have to taste salty for the sodium content to be high. It may be surprising, but bread is one of the most common sources of sodium. So, it is important to read food labels for sodium content when you buy packaged or processed foods. Also, cut down on fast food. If you have blood pressure that is difficult to control on multiple medications, you should consider seeing a hypertension specialist.

Causes of Resistant Hypertension

dated6: What are the main causes of resistant hypertension?

George_Thomas,_MD: Resistant hypertension is the term used to define hypertension that is not controlled on at least three blood pressure medications, including the class of medications called diuretics or water pills, with each medication at maximal tolerated doses. In many cases, ‘resistance’ is not ‘true resistance’ since there could be factors like incorrect measurement, inappropriate medications, too much salt intake or alcohol intake, etc. that lead to ‘resistance.’ If all these issues have been addressed, then your doctor should consider checking you for secondary causes of hypertension, i.e., for hormonal causes, kidney disease, vascular causes, etc.

Olecanku: Are the causes of resistant hypertension reversible? Which are not reversible?

George_Thomas,_MD: Hypertension control involves lifestyle management in addition to medications -- you should maintain a healthy weight, eat a healthy diet (low sodium is key), limit alcohol intake and also be sure that the blood pressure readings are taken accurately.

Age, family history and race are risk factors for hypertension , i.e., older age, strong family history of hypertension, and African-American race are risk factors for hypertension and these are non-modifiable. If you have secondary causes, which includes hormonal causes or vascular causes, these are potentially reversible depending on what you actually have. One point on salt intake—guidelines suggest limiting it to at least less than 2.3 grams of sodium in one day. This is equal to about one teaspoon of salt. Remember that sodium also comes from processed foods—i.e., anything in bags, jars, cans or boxes generally come with a lot of sodium, so you should be careful to read labels.

False Resistant Hypertension

re-wired: What is ‘false’ resistant hypertension?

George_Thomas,_MD: Some common reasons for false resistance or ‘pseudoresistance’ are: incorrect measurement of blood pressure either at home or in the office, incorrect medication intake (including inappropriate combinations of medications or incorrect dosages), blood pressure being high due to excessive salt intake or alcohol intake, and taking medications like NSAIDs (non steroidal anti-inflammatory drugs) which could elevate blood pressure.

Blood Pressure and Autonomic Dysfunction

ernest: My doctor thinks I might have some autonomic dysfunction related to multiple sclerosis as well as hypertension issues. My diastolic pressure usually stays down, but we have not had much luck getting my systolic pressure below the 130 to 145 range. Every change in protocol turns out poorly within two weeks. I end up feeling crummy from a too low blood pressure in the afternoon (around 88/40). My heart rate gets too rapid (in the 90s rather than its normal pacemaker-controlled 60 bpm) or my potassium climbs. Pindolol (Visken®)5 mg twice daily and lisinopril (Prinivil®) 10 mg at bedtime seem to work best at present. Is this level of control generally good enough?

George_Thomas,_MD: Variations in blood pressure due to autonomic dysfunction are generally difficult to manage—the blood pressure tends to be low when you are up and about, and higher when you lie down. It would be difficult to get blood pressure at a certain goal given the variations. In general, the goal would be to adjust your medications, so your standing blood pressures do not drop to a level that makes you feel dizzy and lightheaded. If your systolic is in the 130 to 145 range, that is acceptable. Some of the other strategies that we use specifically in autonomic dysfunction include: advising a gradual rise from lying down to sitting to standing positions, smaller and more frequent meals rather than large meals, compression stockings when you are standing or walking (but not when lying down), avoiding the class of medications called diuretics or water pills (that are otherwise used for blood pressure control) and raising the head of the bed.

Accuracy of Blood Pressure Monitors

Leonard: I was given a blood pressure monitor to use at home. How accurate are they? Also, when I go to my doctor appointment, the blood pressure cuff is often placed over my clothing (like a thin shirt). Is this a good practice or should it be placed next to the skin?

George_Thomas,_MD: There are a number of good home blood pressure monitors. A recent report comparing different monitors can be found at the Consumer Reports® website ( Home blood pressure monitoring is a good idea—especially if your blood pressure tends to be different at home compared to the doctor’s office. You should always take a log of your blood pressure readings to your doctor’s visits, so that the patterns can be assessed. Also, if there is a question of accuracy, please make sure to take your home blood pressure monitor to your doctor’s office so that they can assess accuracy or help calibrate it.

Ideally, blood pressure should be taken over the bare arm. You should be in a seated position, with your back supported, your legs uncrossed and on the floor, your arm should be supported at heart level, and you should be seated for at least five minutes before checking blood pressure in a quiet room with no distractions. You should not have had caffeine, smoked or exercised for at least 30 minutes prior to taking blood pressures.

When to Start Hypertension Treatment

rhdeemdn2: When do you start treating hypertension? My family history has several risk factors, including high cholesterol, diabetes, heart attack, and stroke. My blood pressure goes up and down on different days. For example, my blood pressure will be 158/62, and then normal for a month. Afterward, my blood pressure will be 145/85, and then normal again. This will follow with 150/65 another day. Do I need to be treated? My blood glucose is also between 100 and 126. I was told I am prediabetic. My cholesterol is 250 with the LDL above 100. When do I start taking medicine since I believe I am still healthy?

George_Thomas,_MD: According to current guidelines, if your blood pressure is above 140 systolic (upper number) or 90 diastolic (lower number), then you are considered to have hypertension. It sounds like your blood pressure readings are generally above this range (especially the upper number). If you have tried improving your lifestyle with exercise and weight management, limiting alcohol intake, eating a healthy diet with low salt intake and avoiding smoking, but still have had this pattern of elevated blood pressures for a while (and considering that you have a significant family history of cardiovascular disease), I would suggest talking to your doctor to begin a blood pressure-lowering medication.

Resistant Hypertension Disease Course and Treatment

on my way: Are complications still expected from resistant hypertension even if one is on medications, is watching what she or he eats, exercises, etc.? Or do the treatments— even if not necessarily effective—help keep control of the complications?

George_Thomas,_MD: The goal for blood pressure levels, as it stands now per guidelines, is to be below a level of 140 systolic (upper number) and 90 diastolic (lower number). The goal is below 130 systolic and 80 diastolic if you have diabetes, cardiac disease, or kidney disease. If you are above the goal in spite of being on three or more medications (including a water pill) at effective doses, then you are considered to have resistant hypertension. Complications from hypertension would occur if you are not at goal blood pressures (even though you may be on medications or lifestyle management). You will benefit from seeing a hypertension specialist if you have resistant hypertension.

Symptom Control

anytime: How can swelling in the legs be controlled?

George_Thomas,_MD: It depends on the reason for the swelling. Heart disease, kidney disease or liver disease are some of the common causes. While diuretics or water pills are generally used to control swelling, the treatment should be directed to the underlying cause.

Treatment for Resistant Hypertension

clancek: What are some of the possible treatments for resistant hypertension? My wife is not overweight, watches her diet as carefully as possible and has tried a number of medications with no results. We seem to be out of options.

George_Thomas,_MD: Some of the things to be aware of are correct measurement of blood pressure readings, appropriate medications at effective doses (including the use of diuretics or water pills), and limiting salt intake and alcohol intake. If her blood pressure still remains high, then assessment for secondary causes (hormones, kidney disease and vascular causes) should be done by your doctor. A referral to a hypertension specialist should also be considered for work up of these causes and adjustment of medications.

Jorge: Is there any specific disease that makes treating resistant hypertension more difficult?

George_Thomas,_MD: Secondary causes of hypertension need to be investigated in patients with resistant hypertension—specifically, hormonal causes (like pheochromocytoma or primary aldosteronism), kidney disease and vascular causes (like renal artery stenosis). Keep in mind that some medications tend to elevate blood pressures, including oral contraceptives and NSAIDs (non-steroidal anti-inflammatory drugs).

Exercise and Resistant Hypertension

helpme: Should exercise be avoided if one has resistant hypertension, or does it help if it is done on a regular basis?

George_Thomas,_MD: Exercise need not be avoided for resistant hypertension per se. However, if you have underlying cardiovascular disease, you should check with your physician prior to beginning an exercise regimen. Additionally, if your blood pressure is very high, then it would be prudent to get it under control prior to beginning an exercise regimen. For hypertension per se, exercise and weight management is very helpful.

Research and New Therapy

Monika: Is there any other new research being done for resistant hypertension besides what you just mentioned?

George_Thomas,_MD: Device-based therapy is the hot new area of research -- which is the 2 I mentioned in the above post. Both of these are not medication related. I am not aware of any new medication trials at this time, although some may be on the horizon.

time off: I read something on-line about baroreflex stimulation and catheter-based renal sympathetic denervation as a treatment. I did not really understand it; can you please explain?

George_Thomas,_MD: These are two new device-based therapies for the control of hypertension. Currently, both devices are undergoing extensive research trial evaluations. There is a lot of interest especially in the renal denervation procedure, which I will try to explain. The renal nerves (or kidney nerves) transmit signals back and forth between the brain and the kidney that modulate or control blood pressure responses. The idea of renal denervation is to ablate (or zap) some of these nerves with heat energy, so that this signaling between the brain and the kidney is lowered (but not completely abolished) and thus get more blood pressure control. The procedure has undergone extensive trials in Europe and is actually approved for clinical use there. In the U.S., a research trial is underway for this procedure and is not yet available for clinical use. The results of the trial, which is expected some time next year, will determine whether the FDA approves the procedure. Certainly, the procedure results on the studies look very promising so far.


Moderator: I'm sorry to say that our time with Cleveland Clinic expert Dr. George Thomas is now over. Thank you, Dr. Thomas, for taking your time to answer our questions today about Resistant Hypertension.

George_Thomas,_MD: You’re welcome. It was a pleasure.

For Appointments

If you would like to make an appointment with Dr. Thomas or any of our other nephrologists in the Glickman Urological & Kidney Institute, please call 800.223.2273, extension 46771 or request an appointment online by visiting Thank you!

For More Information

On Cleveland Clinic

The Center for Blood Pressure Disorders within Cleveland Clinic's Department of Nephrology and Hypertension in Glickman Urological & Kidney Institute provides quality patient care for optimal control in patients with severe hypertension and related blood pressure disorders. The center’s advanced approach is highly effective in monitoring and managing patients’ blood pressure.

The Center also offers continuing care for patients with hypertension and/or hypertension-related disease conditions. A team of physicians, nurse practitioners, and physician assistants are prepared to offer total care to the patient with hypertension.

Cleveland Clinic's Glickman Urological & Kidney Institute has a long history of significant expertise in acute and chronic renal failure. The institute offers services in the areas of chronic kidney disease, hypertension, dialysis, kidney transplantation and renal diseases.

Our staff works in a care team model to provide increased availability to physicians and timely consultations for patients. As part of the Glickman Urological and Kidney Institute, the Department of Nephrology and Hypertension is aligned with the departments of Urology and Regional Urology, enabling us to better serve patients in the prevention, diagnosis and treatment of kidney disease.

The Glickman Urological and Kidney Institute at Cleveland Clinic is ranked first in the nation for nephrology by U.S.News & World Report of the nation’s best hospitals 2012-2013.

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This information is provided by Cleveland Clinic as a convenience service only and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. Please remember that this information, in the absence of a visit with a health care professional, must be considered as an educational service only and is not designed to replace a physician's independent judgment about the appropriateness or risks of a procedure for a given patient. The views and opinions expressed by an individual in this forum are not necessarily the views of the Cleveland Clinic institution or other Cleveland Clinic physicians. ©Copyright 1995-2013. The Cleveland Clinic Foundation. All rights reserved.