Description

• Essential hypertension (HTN) is HTN without an identifiable cause; also known as primary HTN and (inappropriately) as benign HTN. Although its importance as a risk factor for cardiovascular and other morbidity and mortality is well established, there is persistent controversy regarding recommended thresholds for diagnosis and treatment.
• HTN is defined (Joint National Committee [JNC] 8) (1) and the International Society of Hypertension) as (all pressures in mm Hg):
  • Age <60 years: systolic BP (SBP) ≥140 and/or diastolic BP (DBP) ≥90 at ≥2 visits
  • Age ≥60 years: SBP ≥150 and/or DBP ≥90 at ≥2 visits
  • With diabetes or chronic kidney disease (CKD): SBP ≥140 and/or DBP ≥90
  • The American College of Cardiology (ACC)/American Heart Association (AHA) uses SBP ≥130 and/or DBP ≥80 as “stage 1 hypertension” which should be treated with exercise and lifestyle modification and reserve medication for when the patient is at “higher risk” which is defined as age ≥65 years, CKD, diabetes, or known cardiovascular disease (CVD).

Geriatric Considerations
Isolated systolic HTN is common. Therapy has been shown to be effective and beneficial at preventing stroke and cardiovascular morbidity and all-cause mortality (2)[A], although target SBP for seniors is higher than in younger patients (~150 mm Hg systolic), and adverse reactions to medications are more frequent. The benefit of therapy has been conclusively demonstrated in older patients for SBP ≥160. Very elderly patients may be at particularly high risk of adverse events associated with pharmaceutical treatment of HTN. Strongest evidence of benefit has been shown with use of thiazide diuretics.

Pediatric Considerations
Defined as SBP or DBP ≥95th percentile on repeated measurements. Measure BP during routine exams beginning at age 3 years. Pre-HTN: SBP or DBP between 90th and 95th percentile

Pregnancy Considerations

• Elevated BP during pregnancy may represent chronic HTN, pregnancy-induced HTN, or preeclampsia. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) are contraindicated.
• Maternal and fetal mortality are reduced with treatment of severe HTN (see topic “Preeclampsia and Eclampsia (Toxemia of Pregnancy)”); preferred agents: labetalol, nifedipine, methyldopa, or hydralazine

Epidemiology

Prevalence
Depending on the definition used, 32–46% of adults in the United States have HTN; incidence and prevalence higher in men

Etiology and Pathophysiology

>90% of cases of HTN have no identified cause. For differential diagnosis and causes of secondary HTN, see “Hypertension, Secondary and Resistant.”

Genetics
BP levels are strongly familial. Familial risk for CVD should be considered.

Risk Factors

Family history, obesity, alcohol use, excess dietary sodium, stress, physical inactivity, tobacco use, insulin resistance, obstructive sleep apnea (OSA)