Hypertension, or high blood pressure, is characterized by the elevation of systolic and/or diastolic arterial blood pressures. It is diagnosed as primary or secondary hypertension. Primary, or essential, hypertension has no known cause. Secondary hypertension has an identifiable cause:21,22

  • Renal disease (e.g., renal parenchymal disease, renal artery stenosis)
  • Adrenal abnormalities (e.g., aldosteronism, Cushing syndrome, pheochromocytoma)
  • Coarctation of the aorta
  • Hyperthyroidism
  • Pre-eclampsia/eclampsia in pregnancy
  • Central nervous system disorders (e.g., trauma, infection, increased intracranial pressure)
  • Autonomic hyperactivity
  • Sleep apnea
  • Medication induced (e.g., COX-2 inhibitors, sympathomimetics, corticosteroid and sex hormones, cyclosporine, tacrolimus)
  • Medication related (e.g., drug-drug interactions, medication noncompliance)

Primary hypertension is of unknown etiology and may be related to genetic and/or environmental factors.23-27 In most populations studied, when environmental and familial risk factors are controlled, blood pressure increases with age.28-32 Hypertension affects over 1 billion people worldwide and approximately one-quarter of American adults. It is estimated that less than 5% have a curable cause.1,33,34 The World Health Organization (WHO) estimates that hypertension is the third leading cause or mortality worldwide.35 Furthermore, the risk of cardiovascular disease doubles for adults age 40-70 years for each rise of 20 mmHg in systolic or 10 mmHg in diastolic.36 Given the prevalence of hypertension, it is critical for oral healthcare providers to understand the current diagnostic categories (Table 1).37,38

Table 1. American Heart Association Hypertension Diagnostic Categories.37,38
CategorySystolic (mmHg)Diastolic (mmHg)
Optimal blood pressure< 120< 80
Normal blood pressure< 130< 85
Prehypertension130 to 13985 to 89
Grade 1 hypertension (mild)140 to 15990 to 99
Grade 2 hypertension (moderate)160 to 179100 to 109
Grade 3 hypertension (severe)> 180 > 110
Isolated systolic hypertension (grade 1)140 to 159< 90
Isolated systolic hypertension (grade 2)> 160< 90