18. HYPERTENSION
1. How often should you screen for hypertension?
Although there is no absolutely correct answer, all people should be screened roughly every
2 years, starting at the age of three.
2. Define hypertension.
Persistent blood pressure greater than 140/90 mmHg. Recent efforts in the "war on hyper-
tension" label a systolic blood pressure of 120-139 mmHg and diastolic pressure of 80-89 mmHg
"prehypertension." Remember that 145/60 mmHg is hypertension, as is 115/95 mmHg (isolated
systolic or diastolic hypertension, respectively). Treatment is needed. In grading the severity of
hypertension, use the worst number, whether it be diastolic or systolic. See the table below for
the 2003 Joint National Committee (JNC) classification.
Systolic BP* Diastolic BP*
(mmHg) (mmHg) Classification
<120 <80 Normal
120-139 80-89 Prehypertension
140-159 90-99 Stage I hypertension
a 160 2 100 Stage II hypertension
*Classification is based on the worst number (e.g., 168/60 mm Hg is considered stage II hypertension
even though diastolic pressure is normal).
3. What is the "three-measurement" rule in the diagnosis of hypertension?
Classically, the blood pressure is measured three time on three separate office visits before
the diagnosis and pharmacologic treatment of hypertension. However, if asked, institute conser-
vative measures (see below) and address associated comorbidities (e.g., obesity, diabetes) after
the first abnormal measurement. There are a few important exceptions to the "start conservative
and remeasure" strategy, however, and more aggressive approaches are gaining favor. If a
patient's blood pressure is greater than 200/120 mmHg (a hypertensive "urgency") or if end-
organ effects are evident (a hypertensive "emergency," see below), treatment should be instituted
immediately. In pregnant woman, preeclampsia may be the cause of hypertension. Waiting to
treat in this setting can have devastating consequences to mother and fetus.
4. What are the conservative (i.e., nonpharmacologic) treatments for hypertension?
Dietary changes (i.e., low salt, low fat, low calorie), reduced smoking and alcohol intake,
weight loss, and exercise may each have a positive effect on blood pressure and, in some cases,
get the patient back into the normotensive range. Medications should be started only after a 1-
to 2-month trial of lifestyle modifications for stage I hypertension. In patients with stage II
hypertension or those with diabetes or renal disease, early pharmacologic treatment is often
preferred.
5. List the first-line medications for treatment of hypertension.
Five classes of drugs are used as first-line therapy: thiazide diuretics, beta blockers,
angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and
calcium channel blockers. Which you should use often depends on the individual patient and his
or her other medical problems.
Drug Class Use in Patients with: Avoid in Patients with:
Thiazides Heart failure, diabetes, high risk for coro- Gout, electrolyte disturbances (e.g.,
nary artery disease or stroke, osteoporosis hyponatremia), pregnancy
Beta blockers Stable angina, acute coronary syndrome/Asthma, chronic obstructive
unstable angina, acute or prior myo- pulmonary disease, heart block, sick
cardial infarction, high risk for coro-sinus syndrome
nary artery disease, atrial tachycardia/
fibrilliation, thyrotoxicosis (short-term),
essential tremor, migraines
ACE inhibitors Heart failure, diabetes, acute coronaryPregnancy, angioedema, renovascular
syndrome/unstable angina, acute or hypertension (may cause renal
prior myocardial infarction, high riskfailure)
for coronary artery disease or stroke,
chronic kidney disease
ARBs Heart failure, diabetes, chronic kidneyPregnancy, renovascular hypertension
disease (may cause renal failure)
Calcium channel Raynaud syndrome, atrial Heart block, sick sinus syndrome,
blockers tachyarrhythmias congestive heart failure (all related
to central-acting agents), pregnancy
Note: ACE inhibitors are first-line agents for congestive heart failure, because they reduce mortality
rates. In diabetes, ACE inhibitors retard progression to nephropathy and neuropathy. All patients with
stable congestive heart failure or diabetes should take an ACE inhibitor (if they can tolerate it) even in
the absence of hypertension.
6. What about women of reproductive age and pregnant women with hypertension?
Labetalol, hydralazine, and alpha-methyldopa are safe. If preeclampsia is present, remember
that magnesium sulfate lowers blood pressure.
7. Define hypertensive urgency. How is it different from hypertensive emergency?
Hypertensive urgency is defined as blood pressure > 200/120 mmHg without symptoms.
Hypertensive emergency is defined as blood pressure > 200/120 mmHg with symptoms or evi-
dence of end-organ damage. Examples: acute left ventricular failure, chest pain or angina,
myocardial infarction, encephalopathy (watch for headaches, confusion, papilledema, mental
status changes, vomiting, blurry vision, dizziness, and/or seizures), or acute renal failure (from
necrotizing arteriolitis, see figure). Both require immediate treatment, but hypertensive emer-
gency is more worrisome. Treat immediately with nitroprusside, nitroglycerin, labetalol, or dia-
zoxide (second-line agent).
Fibrinoid necrosis secondary to malignant hyperten-
sion. This change is due to rapid intimal cell prolifer-
ation with leakage of plasma proteins into and beyond
the arteriolar wall with resultant obliteration of the
wall by intensely eosinophilic amorphous proteina-
ceous material (P) and, often, luminal occlusion .
Damage to the vessel wall may also lead to thrombo-
sis within the lumen. A glomerulus can be seen on the
far right side of the image. (From Stevens A, et al:
Wheater's Basic Histopathology, 4th ed. New York,
Churchill Livingstone, 2002, p 116, with permission.)
8. What causes hypertension?
Roughly 90-95% of cases are idiopathic, multifactorial, or essential hypertension. About
5-10% of cases are due to secondary (known) causes.
