Hypertension

Hypertension Main page
Overview
Causes
Classification Primary Hypertension Secondary Hypertension Hypertensive Emergency Hypertensive Urgency
Screening

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Hypertension is generally defined as an elevated systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg. Hypertension can be chronic or acute. While 95% of the cases of chronic hypertension are primary, 5% of chronic hypertension is secondary to other underlying causes. Hypertensive crisis is the acute elevation of blood pressure and it can be classified into hypertensive emergency or hypertensive urgency when end organ damage is present or absent respectively.

Causes

When a full evaluation yields no clear etiology for the elevated blood pressure, the latter is identified as primary hypertension. Secondary hypertension can be caused by:

• Apnea
• Hyperaldosteronism
• Renal failure
• Coarctation of aorta
• Cushing's syndrome
• Drugs
• Diet
• Pheochromocytoma
• Obesity
• Hyperparathyroidism

For detailed causes of secondary hypertension, click here.

Classification

For more details about each specific type of hypertension, click on the links in blue in the algorithm below.
In order to distinguish primary hypertension from secondary hypertension, click here.

Hypertension

Chronic hypertension

Hypertensive crisis Acute elevation of blood pressure - Systolic blood pressure >180 mm Hg OR - Diastolic blood pressure >120 mm Hg

Primary hypertension (also known as essential hypertension) (95% of the cases)

Secondary hypertension (5% of the cases)

Hypertensive emergency Evidence of end organ damage

Hypertensive urgency No evidence of end organ damage

Screening

The age to begin screening for hypertension varies between 13-20 years of age, according to different authorities. Generally, hypertension is defined as SBP > 140 mmHg and/or DBP > 90 mmHg. In specific populations, however, routine follow-up target BP may be different; and initiation of treatment may be considered at even lower BP values than those considered for the normal population.