Chronic hypertension pathophysiology

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]; Assistant Editor-In-Chief: Taylor Palmieri

Overview

While the mechanisms underlying secondary hypertension are well understood, the mechanisms underlying primary or essential hypertension are poorly understood.

Time Dependence of Pathophysiology

• Cardiac output is raised early in the disease course, while total peripheral resistance (TPR) is normal.
• Over time cardiac output drops to normal levels but TPR is increased. Three theories have been proposed to explain this:

  Inability of the kidneys to excrete sodium, resulting in natriuretic factors such as Atrial Natriuretic Factor being secreted to promote salt excretion with the side-effect of raising total peripheral resistance.

  An overactive renin / angiotension system leads to vasoconstriction and retention of sodium and water. The increase in blood volume leads to hypertension.

  An overactive sympathetic nervous system, leading to increased stress responses.

Genetics

Hypertension is highly heritable and polygenic (caused by more than one gene) and a few candidate genes have been postulated in the etiology of this condition.