As blood flows through arteries, it pushes against the arterial walls with force. This force is referred to as blood pressure. High blood pressure occurs when this pressure remains elevated over time. This condition can damage organs, such as the kidneys and eyes. The National Heart, Lung and Blood Institute reports that about one-third of American adults have high blood pressure. This condition has no cure but is managed with certain drugs.
Fluid Disposal
"Reversing Hypertension: A Vital New Program to Prevent, Treat, and Reduce High Blood Pressure" by Julian Whitaker explains that a diet that promotes salt retention in the body--such as a high-fat or high-sodium diet--can lead to water retention and an increase in blood volume. When blood volume goes up, blood pressure incresases as well. Diuretics are high blood pressure medicines that treat high blood pressure by reducing blood volume. They stimulate the body to dispose of excess water and salt in urine.
Expanding Blood Vessels
"High Blood Pressure For Dummies" by Alan L. Rubin suggests that high blood pressure is associated with narrow or constricted blood vessels. This effect may be the body's response to a high blood volume or slight changes in body chemistry, such as an increase in angiotensin II--a hormone produced by the kidneys when blood pressure is low. Beta blockers are a class of hypertension medications that reduce blood pressure by making the blood vessels expand. They also reduce the force with which the heart beats and make the heart beat slowly.
Enzyme Inhibition
When blood volume is low, the kidneys secrete an enzyme called renin. This enzyme acts on angiotensinogen, a protein secreted by the liver. Through a series of reactions, another enzyme called an angiotensin converting enzyme then converts this protein to angiotensin II. Angiotensin II makes the blood vessels constrict, raising blood pressure. Angiotensin-converting enzyme inhibitors or ACE inhibitors are a class of drugs used to treat high blood pressure. They work by inhibiting the action of the angiotensin-converting enzyme and the production of angiotensin II. This action prevents constriction of the blood vessels and lowers high blood pressure.
References
- National Heart, Lung and Blood Institute
- Mayo Clinic: High Blood Pressure-- Treatment and Drugs
- "High Blood Pressure for Dummies"; Alan L. Rubin; 2007
- "Reversing Hypertension: A Vital New Program to Prevent, Treat, and Reduce High Blood Pressure"; Julian Whitaker; 2001
