Hypertension (HTN) or high blood pressure, sometimes called arterial hypertension, is a chronic medical condition in which the blood pressure in the arteries is elevated. Blood pressure is summarized by two measurements, systolic and diastolic, which depend on whether the heart muscle is contracting (systole) or relaxed between beats (diastole). This equals the maximum and minimum pressure, respectively. There are different definitions of the normal range of blood pressure. Normal blood pressure at rest is within the range of 100 - 140 mmHg systolic (top reading) and 60 - 90 mmHg diastolic (bottom reading). High blood pressure is said to be present if it is often at or above 140/90 mmHg.
What is Hypertension
Hypertension, also referred to as high blood pressure, HTN or HPN, is a medical condition in which the blood pressure is chronically elevated.
In current usage, the word hypertension without a qualifier normally refers to arterial hypertension. Arteries are vessels that carry blood from the pumping heart to all the tissues and organs of the body.
Hypertension can be classified either essential (primary) or secondary.
Hypertension risk factors include obesity, drinking too much alcohol, smoking, and family history.
In individuals older than 50 years, hypertension is considered to be present when a person's systolic blood pressure is consistently 140 mm Hg or greater or when the diastolic blood pressure is consistently 90 mm Hg or greater. (see our blood pressure reading chart)
Although no specific medical cause can be determined in essential hypertension, it often has several contributing factors. These include obesity, salt sensitivity, renin homeostasis, insulin resistance, genetics, and age. Over time, the number of collagen fibers in artery and arteriole walls increases, making blood vessels stiffer. With the reduced elasticity comes a smaller cross-sectional area in systole, and so a raised mean arterial blood pressure.
Over 91% of adult hypertension has no clear cause and is therefore called essential/primary hypertension. Often, it is part of the metabolic "syndrome X" in patients with insulin resistance: it occurs in combination with diabetes mellitus (type 2), combined hyperlipidemia and central obesity.
Pulmonary hypertension (PH) is an increase in blood pressure in the pulmonary artery, pulmonary vein, or pulmonary capillaries, together known as the lung vasculature, leading to shortness of breath, dizziness, fainting, and other symptoms, all of which are exacerbated by exertion. Pulmonary hypertension can be a severe disease with a markedly decreased exercise tolerance and heart failure.
The degree to which hypertension can be prevented depends on a number of features including:
The American Heart Association estimates high blood pressure affects approximately one in three adults in the United States - 73 million people. High blood pressure is also estimated to affect about two million American teens and children, and the Journal of the American Medical Association reports that many are under-diagnosed. Hypertension is clearly a major public health problem.
The color red ribbon is symbol of hypertension as well as general heart disease awareness, and February is American Heart Month dedicated to raising awareness about cardiovascular diseases.