When it comes to the differentiation and diagnosis of hypertension,
referred to colloquially as “the silent killer,” physicians and
cardiologists must be aware that hypertension and elevated BP are not always
linked, and that there are various forms of hypertension.
“Hypertension is more than just elevated BP,” George L.
Bakris, MD, professor of medicine and director of the Hypertensive Diseases
Unit in the department of medicine at the University of Chicago Pritzker School
of Medicine, said in an interview. “When a patient presents with elevated
BP, they do not necessarily have hypertension. Elevated BP could be transient
Although high BP is a manifestation of hypertension, hypertension is a
genetically mediated disease, Bakris told Cardiology Today.
George L. Bakris, MD, said distinguishing between the numerous forms of
hypertension is essential to proper care.
Photo coutesy of:
George L. Bakris, MD
“It is important to not only educate health care professionals
about the difference between the two, but to also convey this message and
prevention efforts to our patients,” said Bakris, who is the current
president of the American Society of Hypertension and an Editorial Board member
for Cardiology Today.
Rising rates of high BP are seen across the country, but health care
professionals are also seeing diagnosis of hypertension in younger populations
compared with years past. According to the most recent results of the National
Health and Nutrition Examination Survey, 29% of US adults aged at least 18
years have hypertension — a number that equates to about 70 million.
Globally, 26.4% of the adult population (972 million) had hypertension more
than a decade ago, and the number of adults with hypertension is expected to
increase to 1.56 billion in 2025, according to a study by Kearney and
colleagues that was published in The Lancet.
It is now more important than ever to properly delineate the difference
between spiked BP, diagnosable hypertension and to distinguish between the
various forms. Cardiology Today spoke with several experts in the
arena on this topic.
Coined essential hypertension nearly 100 years ago, primary hypertension
is typically a genetic disease, with susceptibility increasing based on
“The term essential hypertension is no longer in vogue; it evolved
in the early 1920s or 1930s with the notion that older people who were living
longer had elevations in BP,” Bakris said. “Back then, the doctors
felt it was ‘essential’ because their pipes were getting rusty and
needed more infusion, hence the term essential. Now, though, we know that is
not true, so it is termed primary hypertension.”
Primary hypertension is seen approximately 95% of the time, ranking as
the most commonly occurring form of hypertension, and refers to elevated BP
from multiple abnormalities in the regulatory functions, according to Shawna
D. Nesbitt, MD, MS, associate professor of internal medicine, division of
cardiology hypertension section, at the University of Texas Southwestern. These
abnormalities may vary from dysfunction in calcium, potassium or sodium levels,
vascular contractions, hormonal elevations and central nervous system
“Primary hypertension is pervasive across all races and both
genders,” Nesbitt said. “While treatable, primary hypertension is not
curable, and the goal of treatment is to prevent the key consequences of
elevated BP such as kidney disease, stroke or MI.”
Secondary hypertension, however, is second to primary hypertension and
occurs when the patient has no family history of hypertension, with no obvious
reasons for a diagnosis.
“Usually, these people have secondary hypertension because it is
secondary to an endocrine problem or a renal problem,” Bakris said.
William B. White
William B. White, MD, professor and division chief of
hypertension and clinical pharmacology at the Pat and Jim Calhoun Cardiology
Center, University of Connecticut School of Medicine, said secondary
hypertension refers to a discernible underlying cause of BP elevation that may
include, but is not limited to, renal artery stenosis, a benign tumor on the
adrenal gland, primary aldosteronism, pheochromocytoma, hyperthyroidism or the
use of BP-raising drugs.
If a secondary condition is diagnosed and curable, then removing this
cause is typically associated with marked improvement in hypertension.
According to Joel Handler, MD, clinical leader for the Kaiser
Permanente national hypertension program and the Kaiser Permanente Southern
California hypertension program, a common problem for practitioners is clinical
“Many factors are responsible for BP measurement variability; among
those are white-coat, reactive and masked hypertension,” Handler said.
White-coat hypertension is a form that occurs when the patient’s BP
in a medical environment, such as a physician’s office or hospital
setting, is more than 10 mm Hg to 15 mm Hg higher than it is in other
environments. This form of hypertension carries less CV risk than true
hypertension, but that risk appears to be intermediate and possibly predictive
of the future development of true hypertension, according to Handler.
In addition, patients with treated hypertension can still have a
white-coat effect. One confounding factor with white-coat form is that the
variability in the response of the BP is not predictable, making it extremely
hard to measure and treat.
Physicians may have also heard the term reactive hypertension, or
reactive elevations or spikes in BP, which is caused by a stimulus. Bakris
said, however, that there is no such thing as a diagnosed reactive form of
“This is a prime example of where the definitions of hypertension
and high BP get muddled,” he said. “Blood pressure becomes elevated
during a stressful situation.”
This form is often interchanged with white-coat hypertension, given that
it occurs in reaction to a setting or event, according to Nesbitt. It is more
commonly seen in patients who experience pain after surgery, anxiety or
psychiatric disorders but do not have diagnosed hypertension.
“Importantly, we shouldn’t be quick to give BP medication
because there may be an underlying condition that is a stimulation of the
sympathetic nervous system,” she said.
Physicians should first do a full workup, including a genetics
evaluation, and monitor the patient using a 24-hour ambulatory device, if
Typically seen among the black population with kidney disease or among
young people with no history of high BP, masked hypertension is the inverse of
white-coat hypertension and is described by normal BP readings in the presence
of the health care professional and elevated out-of-office BPs, according to
“Similar to white-coat hypertension, masked hypertension appears to
be an intermediate risk factor,” he said. “Though masked hypertension
is more worrisome in the presence of target organ damage such as chronic kidney
disease, studies have not been performed to show benefit from antihypertensive
Nesbitt said each one of these forms of hypertension are all very
different, so to define white-coat vs. mask vs. reactive hypertension may be
difficult, but the most important diagnostic tool to differentiate these forms
is an ambulatory BP monitor or home BP monitoring.
Another form of hypertension that is more antiquated, according to
Bakris, is accelerated hypertension. This form refers to a patient who was
diagnosed with primary hypertension that was controlled at one point for a
period of time, and now the patient’s BP is elevated despite no changes in
medication or lifestyle. The patient experiences progressive increases in BP
that can top out at extremely high levels of 240 mm Hg/120 mm Hg in a
relatively short period of time.
“If you have a patient with this situation, you have to evaluate
whether there was a change in dietary intake, such as increased salt
consumption or weight changes. If those can be ruled out, then look immediately
at secondary causes such as alternative health issues,” Bakris said.
“Accelerated hypertension is not uncommon among people with kidney disease
or changes in their lifestyle.”
Accelerated hypertension is often intermingled with malignant
hypertension, White said. Patients may present with acute retinal hemorrhages,
papilledema of the optic disc, acute pulmonary edema and hypertensive
“The term malignant hypertension was used by pathologists who noted
that these patients have acute target organ injury associated with fibrinoid
necrosis of the wall of an artery,” he said. “This is a serious and
Malignant hypertension is a “distinctly unusual” form of
hypertension, according to Bakris, and is typically seen in a patient with a
markedly elevated BP reading of 170 mm Hg/110 mm Hg or higher. This form of
hypertension is more common in patients aged 50 years and older.
John D. Bisognano
Similarly, patients who present with elevated BP but are asymptomatic
may have hypertensive urgency. Hypertensive urgency is a situation in which BP
is more than 180 mm Hg to 200 mm Hg systolic and/or more than 110 mm Hg to 120
mm Hg diastolic. The cause for concern would be that if BP goes much higher,
the patient may experience an ill effect, according to John D. Bisognano,
MD, PhD, director of medicine and cardiology at University of Rochester
Medical School, New York.
“This is different than a hypertension emergency, a term often used
interchangeably with malignant hypertension, where there is actual damage to an
organ occurring because of the elevated BP,” Bisognano told
The difference between hypertensive emergency and urgency, which share
similar BP elevations, is active target organ damage, such as stroke,
encephalopathy, acute coronary ischemia, acute pulmonary edema, aortic
dissection, blindness and acute renal failure.
Isolated systolic hypertension, also known as systolic hypertension, is
more commonly seen in people aged older than 60 years who have stiffened
vessels with a BP reading of 140 mm Hg/90 mm Hg. The systolic number is
elevated; the diastolic number is not.
“It is evident that the systolic BP is a more potent risk factor
than the diastolic BP for predicting stroke, HF and other consequences of
hypertension,” White told Cardiology Today. “This
condition is, therefore, serious if left untreated.”
Resistant hypertension is classically defined as having hypertension
that persists despite the use of three or more pharmacologically complementary
antihypertensive drugs at maximally tolerated doses, one of which includes a
diuretic. BP reading is also typically more than 140 mm Hg/90 mm Hg in an
otherwise healthy patient. For this type of patient, renal nerve ablation may
be warranted, along with a review of other medications.
“This is actually fairly common in practice and is an issue if the
BP remains elevated for a prolonged period of time,” White said.
“Resistant hypertension is often associated with secondary
Pseudo-hypertension describes a rare condition in which the blood vessel
walls are so stiff that the BP cuff cannot compress the artery without exerting
very high levels of external pressure. BP values are often much higher than
what would be detected via catheter and do not actually reflect the actual BP
measurement in the artery.
It was coined in the late 1980s and early 1990s, according to Bakris,
and is also seen exclusively in the elderly with stiff vessels but who also
experience various adverse effects from the elevated BP.
“Pseudo-hypertension is not used much anymore, certainly not in the
medical literature, because research has shown that those people have isolated
systolic hypertension,” he said. “It has become a passé
According to White, the diagnoses of all of these forms of hypertension
are relatively heterogeneous.
“We would like to see enhanced use of out-of-office monitoring,
thought to improve diagnostic precision, conducted by both self-BP monitoring,
as well as 24-hour monitoring when appropriate,” he said.
Proper diagnosis of any of the aforementioned forms of hypertension
should not be based on a single reading. A patient’s age, weight,
ethnicity, family history, smoking status and other lifestyle factors can
change a physician’s perspective when determining which form of
hypertension the patient may have, according to Nesbitt.
“Physicians need to approach each patient as an individual who may
have a unique form of hypertension and listen for the various cues that relate
to the specific types of hypertension,” she said. “Listening will
help you learn much more about how to select which test to perform or not
perform based on their examination.”
It is important to actively evaluate and treat hypertension in all
populations, regardless of age, ethnicity and gender, and not write elevated
BPs off to a white-coat effect, according to Bisognano.
“Never miss the opportunity to treat a patient’s
hypertension,” he said. “If their numbers are above the goals,
reinforce a healthy lifestyle, but check their BP again soon.” –
by Tara Grassia
For more information:
- Chobanian A. Hypertension. 2003;42:1206-1252.
- Egan B. JAMA. 2010;303:2043-2050.
- Flack J. Hypertension. 2010;56:780-800.
- Kearney P. Lancet. 2005;365:217-223.
Disclosures: Dr. Bisognano is a consultant for CVRx. Dr. Nesbitt
is a speaker/consultant for Novartis, a consultant for Daiichi Sankyo, a
speaker for Boehringer Ingelheim, and a speaker for Gilead. Drs. Bakris,
Handler and White report no relevant financial disclosures.