Normal blood pressure (BP) in adults can be defined as systolic BP <120 mm Hg and diastolic BP <80 mm Hg. Elevated BP is defined as systolic BP between 120 and 129 mm Hg or diastolic BP <80 mm Hg. Hypertension (HTN) can be divided into (1) stage 1: Systolic BP from 130 to 139 mm Hg or diastolic BP from 80 to 89 mm Hg and (2) stage 2: Systolic BP ≥140 mm Hg or diastolic BP ≥90 mm Hg. This definition is based on accurate measurements and average of ≥2 readings on ≥2 occasions.

HTN

Essential hypertension

Idiopathic hypertension

High BP

• In the U.S., 50% of people aged 60 to 69 yr and ∼75% of people >70 yr of age are affected by HTN. Worldwide, it is estimated that 41% of people ages 35 to 70 yr have HTN, and only 46.5% of them are aware of it.
• Peak prevalence increases with age and is highest among non-Hispanic Black adults in the U.S.
• HTN is linked with a higher risk of heart attack, stroke, heart failure, and kidney disease.

Physical examination may be entirely within normal limits, except for the presence of elevated BP. A proper initial physical examination on a hypertensive patient should include the following:

• The BP should be measured with an appropriately sized cuff (bladder of the cuff should cover at least two thirds of the circumference of the arm) and taken in both arms (the higher of the readings being used). Table 1 describes BP cuff size and error in measurement.
• The BP should be measured twice on each visit and separated by at least 1 to 2 min to allow the return of trapped blood.
• The patient should be seated in a calm environment for at least 5 min with the arm in which BP is measured rested on support level with the heart.
• Postural BP change should always be recorded in the elderly to diagnose postural hypotension. This is assessed by taking BP in supine (after 5-min rest) and standing (after 2 min) positions. A drop of ≥20 mm Hg in systolic, a drop of ≥10 mm Hg diastolic BP, or symptoms of cerebral hypoperfusion is suggestive of postural (orthostatic) hypotension.
• A diagnosis of HTN may be established if the BP is markedly elevated (>180/110 mm Hg) or has evidence of end organ damage; otherwise such a diagnosis should wait until BP is found elevated on >2 readings on >2 different occasions.
• Nonoffice (home, workplace, 24-h ambulatory) BP determination to establish the pattern of HTN (sustained, “white coat,” or “masked” HTN) in selected patients.
• Measure heart rate, height, weight, body mass index, and waist circumference.
• Some general clinical clues for when to screen for secondary HTN include:
  1. Severe or resistant HTN
  2. An acute rise in BP developing in a patient with previous stable BP
  3. Age less than 30 yr, nonobese, non-Black with no family history of HTN
  4. Sudden onset or accelerated HTN
  5. Age of onset before puberty. If above is suspected, additional tests for secondary HTN should be done, including renin, aldosterone, cortisol levels, 24-h urine metanephrines, and serum catecholamines
• Physical examination should include searching for secondary causes, and sequelae of HTN.
• Examine skin for the presence of café-au-lait spots (neurofibromatosis), uremic appearance (renal failure), and violaceous striae (Cushing syndrome).
• Perform careful funduscopic examination; check for papilledema, retinal exudates, hemorrhages, arterial narrowing, arteriovenous compression.
• Examine neck for carotid bruits, distended neck veins, and enlarged thyroid gland.
• Perform extensive cardiopulmonary examination: Check for a laterally displaced point of maximal intensity, an S3 or S4, and valvular murmurs.
• Palpate abdomen for renal masses (pheochromocytoma, polycystic kidneys), and auscultate for bruit over the aorta and renal arteries.
• Examine arterial pulses (dilated or absent femoral pulses and BP greater in upper extremities than lower extremities suggest aortic coarctation).
• Look for truncal obesity (Cushing syndrome) and pedal edema (congestive heart failure [CHF]).
• Table 2 provides a guide to evaluation of identifiable causes of HTN.
• Table 3 summarizes clinical clues to guide the investigation in young patients with hypertension that has a potentially hereditary cause.

• Essential (primary) HTN (85%)
• Drug induced or drug related (5%)
  1. NSAIDs
  2. Oral contraceptives
  3. Corticosteroids
• Renal HTN (5%)
  1. Renal parenchymal disease (3%)
  2. Renovascular HTN (RVH) (<2%)
• Endocrine (<2%) (Table 4)
  1. Primary aldosteronism (at least 5%)
  2. Pheochromocytoma (0.2%)
  3. Cushing syndrome and long-term steroid therapy (0.2%)
  4. Hyperparathyroidism or thyroid disease (0.2%)
• Coarctation of the aorta (0.2%)
• Causes of secondary hypertension are summarized in Box 1

• The objective for the initial evaluation of HTN is to establish the diagnosis and stage of HTN. Table 5 summarizes initial laboratory evaluation of the hypertensive patient.
• Gather office and nonoffice BP readings, assess presence of target organ damage (TOD), assess the level of global cardiovascular disease risk, and produce a plan for individualized monitoring and therapy.
• Patient counseling and education should be prominent features of the initial evaluation.
• Pertinent history:
  1. Age of onset of HTN, previous antihypertensive therapy
  2. Family history of HTN, stroke, cardiovascular disease
• Diet, salt intake, caffeine, alcohol, drugs (e.g., oral contraceptives, NSAIDs, decongestants, steroids).
• Occupation, lifestyle, pain, socioeconomic status, psychologic factors.
• Other cardiovascular risk factors: Hyperlipidemia, obesity, diabetes mellitus.
• Symptoms of secondary HTN:
  1. Headache, palpitations, excessive perspiration (possible pheochromocytoma)
  2. Weakness, polyuria (consider hyperaldosteronism)
  3. Claudication of lower extremities (seen with coarctation of aorta)
  4. Loud snoring, daytime somnolence, morning confusion (may warrant evaluation for sleep apnea)

• Routine laboratory tests recommended before initiating therapy include:
  1. Urinalysis with microscopic evaluation; for signs of glomerulopathy
  2. Basic metabolic panel and calcium; for signs of kidney damage, hypokalemia (primary aldosteronism and Cushing syndrome), hypercalcemia (hyperparathyroid)
  3. CBC
  4. Screening for coexisting diseases that may adversely affect prognosis; hemoglobin A_1c or fasting glucose level, serum lipid panel
  5. Optional tests include measurement of urinary albumin or albumin/creatinine ratio

• ECG: Check for presence of left ventricular hypertrophy (LVH) with strain pattern.
• Renal duplex ultrasonography, CT angiography or magnetic resonance angiography of the renal arteries in suspected renovascular hypertension (renal artery stenosis) may be considered.

Lifestyle modifications (the initial treatment of hypertension should focus on lifestyle modifications [Table 6]):

• Weight loss if overweight (target body mass index [BMI] <25).
• Limit alcohol intake to 1 oz of ethanol per day (<2 drinks/day) in men or 0.5 oz (<1 drink/day) in women.
• Regular aerobic exercise (at least 30 min/day on most days).
• Reduce sodium intake to <100 mmol/day (<1.5 g of sodium/day).
• Maintain adequate dietary potassium (>3500 mg/day) intake in patients with normal kidney function.
• Smoking cessation.
• The BP reduction seen ranges from 2 to 20 mm Hg, most significant with substantial weight loss and the implementation of the Dietary Approaches to Stop Hypertension (DASH) eating plan, which relies on a diet high in fruits and vegetables, moderate in low-fat dairy products, and low in animal protein but with substantial amount of plant protein from legumes and nuts.

• Multiple recent consensus documents regarding BP goals and when to initiate treatment have been published. Antihypertensive medications are summarized in Table 7. Antihypertensive choices in the setting of cardiovascular comorbidity are described in Table 8.
  1. For low-risk adults (no ASCVD or 10-yr CVD risk <10%) with stage 1 hypertension, management should start with nonpharmacologic therapy. If BP remains uncontrolled after 3 to 6 mo, then consider starting pharmacologic therapy.¹
  2. For adults with confirmed hypertension and known cardiovascular disease (CVD) or 10-yr atherosclerotic cardiovascular disease (ASCVD) event risk of 10% or higher, a BP target of less than 130/80 mm Hg is recommended.²
  3. For adults with confirmed hypertension without additional markers of increased CVD risk, a BP target of less than 130/80 mm Hg may be reasonable.
• In addition, initiation of therapy recommendations is as follows:
  1. Use of BP-lowering medication is recommended for primary prevention of CVD in adults with no history of CVD and with an estimated 10-yr ASCVD risk <10% and stage 2 HTN.
  2. Use of BP-lowering medications is recommended for secondary prevention of recurrent CVD events in patients with clinical CVD and for primary prevention in adults with an estimated 10-yr ASCVD risk of 10% or higher and stage 1 HTN.
  3. Initiate antihypertensive drug therapy with two first-line agents of different classes for adults with stage 2 HTN and BP more than 20/10 mm Hg higher than their target.
  4. Patients with diabetes mellitus and chronic kidney disease are considered high risk.
  5. In the general non-Black population, preferred initial agents are thiazide-type diuretics, angiotensin-converting enzyme inhibitors (ACEI), calcium channel blockers (CCBs), or angiotensin receptor blockers (ARBs). ACEI or ARBs are preferred initial agents in diabetics and those with chronic kidney disease (CKD) in this population.³
  6. Preferred initial agents in the Black population (including diabetics) are thiazide-type diuretics or CCBs.
  7. When selecting drugs, try to give once per day dosages to improve compliance. Also consider the cost of the medication, metabolic and subjective side effects, and drug-drug interactions.
• The major advantages and limitations of each class of drugs are described as follows:
  1. Thiazide diuretics:
     1. Advantages: Inexpensive, once-daily dosing. Useful in edematous states, CHF, chronic renal disease, elderly patients (decreased incidence of hip fractures in elderly patients)
     2. Disadvantages: Significant adverse metabolic effects (hypokalemia), increased risk of cardiac arrhythmias, sexual dysfunction, gout flares, possible adverse effects on lipids and glucose levels
  2. β-Blockers:
     1. Advantages: Ideal in hypertensive patients with ischemic heart disease or status post myocardial infarction (MI); favored in hyperkinetic, young patients (resting tachycardia, wide pulse pressure, hyperdynamic heart) and stable CHF patients
     2. Disadvantages: Adverse effect on quality of life (increased incidence of fatigue, depression, impotence), bronchospasm, hypoglycemia, peripheral vascular disease, adverse effects on lipids, masking of signs and symptoms of hypoglycemia in diabetics
  3. Calcium antagonists:
     1. Advantages: Helpful in hypertensive patients with ischemic heart disease. Generally favorable effect on quality of life; can be used in patients with bronchospastic disorders, renal disease, peripheral vascular disease, metabolic disorders, and salt sensitivity. CCBs’ BP-lowering effect is independent of Na⁺ intake.
     2. Disadvantages: Diltiazem and verapamil should be avoided in patients with CHF caused by systolic dysfunction because of their negative inotropic effects; pedal edema may occur with nifedipine and amlodipine; constipation can be severe in elderly patients receiving verapamil. CCB-related edema is positional in nature and improves with lying position; additional strategies include switching CCB classes, reducing dosage, giving the medication later in the day, and adding a venodilator (nitrates, an ACE, or an ARB); diuretics may improve edema, but at the expense of a reduction in plasma volume.
  4. ACE inhibitors:
     1. Advantages: First-line therapy for patients with left ventricular dysfunction, helpful in prevention of diabetic renal disease; effective in decreasing LVH, and remodeling.
     2. Disadvantages: Dry cough is a frequent side effect (5% to 20% of patients); hyperkalemia may occur in patients with diabetes or severe renal insufficiency; hypotension may occur in volume-depleted patients; increased risk of renal failure in patients with renal artery stenosis; contraindicated in pregnancy.
  5. ARBs:
     1. Advantages: Well tolerated, favorable impact on quality of life; useful in patients unable to tolerate ACE inhibitors because of persistent cough and in CHF and diabetic patients; single daily dose. An episode of renal insufficiency with ACE inhibitors does not rule out future therapy with an ARB unless high-grade bilateral renal artery stenosis exists.
     2. Disadvantages: Hypotension may occur in volume-depleted patients; hyperkalemia; risk of renal failure in renal artery stenosis; contraindicated in pregnancy.
  6. Alpha-adrenergic blockers:
     1. Advantages: No adverse effect on blood lipids or insulin sensitivity; helpful in benign prostatic hypertrophy.
     2. Disadvantages: Postural hypotension, sedation; syncope can be avoided by giving an initial low dose at bedtime. Generally considered third- or fourth-line agent.
  7. Central alpha-antagonists:
     1. Oral clonidine mainstay of therapy for hypertensive urgencies because of the ease of administration and relative safety.
     2. Transdermal clonidine; useful in management of labile HTN, the hospitalized patient who cannot take medications by mouth, and patients subject to early-morning BP surges. At equivalent doses, transdermal clonidine is more apt to precipitate salt and water retention than is the case with oral clonidine.
     3. Dose beyond 0.4 mg causes fatigue, sedation, dry mouth, salt and water retention, and rebound HTN upon abrupt termination of the medication.
  8. Combined α- and β-adrenergic receptor blockers:
     1. Labetalol, nebivolol, and carvedilol: Use is reserved to treat complicated hypertensive patient when an antihypertensive effect beyond β-blockade is sought. IV labetalol is used for hypertensive emergencies. Carvedilol is shown to have less adverse effect on glycemic control than metoprolol and to reduce urinary protein excretion in hypertensive diabetic patients.
  9. Direct-acting smooth muscle relaxant: Hydralazine
     1. Advantages: Beneficial in Black patients when used with isosorbide dinitrate.
     2. Disadvantages: May lead to reflex tachycardia, worsening ischemia (best used with nitrates), at higher doses or with renal failure can lead to a reversible drug-induced lupus.
  10. Renin inhibitors: Newest class of antihypertensives (Aliskiren):
      1. Advantages: Generally well tolerated; once-daily dosing; can be used alone or in combination with other antihypertensive agents (avoid combining with ACE inhibitors or ARBs given increase of hyperkalemia).
      2. Disadvantages: Contraindicated in pregnancy; should not be used in patients with impaired renal function; excessive cost; paucity of cardiovascular outcomes data showing benefit.

• “Masked hypertension” refers to the detection of HTN with home or ambulatory monitoring. Up to 40% of patients with BP less than 140/90 mm Hg in the office may have masked hypertension. Automated BP monitors are useful to screen for masked HTN.
• “White coat hypertension” is defined as an elevated BP during medical office examination, whereas BP is in the normal range while at home. Its prevalence is as high as 30% among patients with an elevated BP in the office. These patients are at increased risk for overt HTN.
• For patients with HTN, every 20/10 mm Hg increase in BP doubles the risk of cardiovascular events.
• Most patients will require at least two medications for BP control.
• If BP is greater than 20/10 mm Hg above goal, therapy should be initiated with two drugs.
• Resistant HTN: HTN is considered resistant if the BP cannot be reduced below target levels in patients who are compliant with an optimal triple-drug regimen that includes a diuretic. Terms refractory and resistant are used interchangeably. Causes include pseudohypertension, measurement artifact, medication nonadherence, volume overload, and secondary HTN.
  1. Pseudohypertension in elderly: Hardened and sclerotic artery is not compressible; hence, falsely elevates BP measurement artifact.
  2. Measurement artifact: BP taken incorrectly (small cuff, improper support).
• Renal sympathetic denervation: A blinded trial did not show a significant reduction of systolic BP in patients with resistant hypertension 6 mo after renal artery denervation as compared with a sham control.⁴
• Barriers to BP control: System issues, provider issues, patient issues, and behavior issues. The rate at which physicians adopt recommended changes based on evidence-based findings can be quite slow and has been properly described as “clinical inertia.”
• Indications for specialist referral for patients with HTN are described in Table 12.
• U.S. guidelines for the treatment of HTN recommend the following²:
  1. Use of BP-lowering medication for secondary prevention in patients with cardiovascular disease and average SBP ≥130 mm Hg or DBP ≥80 mm Hg, and for primary prevention in adults with an estimated 10-yr ASCVD risk of >10% and an average SBP ≥130 mm Hg or DBP ≥80 mm Hg.
  2. In patients with no history of cardiovascular disease and an estimated 10-yr ASCVD risk <10%, BP-lowering medication is recommended for those with an average SBP ≥140 mm Hg or an average DBP ≥90 mm Hg.

High Blood Pressure (Patient Information)

High Blood Pressure-Child (Patient Information)

Eclampsia (Related Key Topic)

Pheochromocytoma (Related Key Topic)

Preeclampsia (Related Key Topic)

Renal Artery Stenosis (Related Key Topic)