Showing posts with label High Blood Pressure. Show all posts
Showing posts with label High Blood Pressure. Show all posts

Wednesday, October 10, 2007

High blood pressure complications

High blood pressure sometimes produces headaches, spots before the eyes, dizzy spells, or nose bleeds, but these symptoms are not major concerns. However, high blood pressure that persists over a period of years accelerates arteriosclerosis, which can be serious because it is a major predisposition to stroke, heart attack, kidney disease, poor circulation in the legs, and heart failure. In response to a long period of high pressure, the heart gradually increases in size as it attempts to do heavier-than-normal work. Eventually the workload becomes too great, pressure cannot be maintained, the heart fails, the lungs become congested, and breathing becomes difficult. Thus, the complications of high blood pressure are much more serious problems than the pressure itself.

High blood pressure causes

Whether young or old, each of us experiences changes in blood pressure throughout the day. It is usually lower at night when we sleep and higher during waking hours. Psychological stress can temporarily increase the pressure, although even a relaxed person in a quiet room may experience increased or decreased pressure for no obvious reason. Blood pressure also varies considerably among different individuals, tending to vary more widely in younger than in older people. This may reflect older persons' greater experience in coping with the contingencies of day-to-day living.

In addition to momentary fluctuations, the average blood pressure over a period of time also varies from one individual to another. It is this average pressure that physicians seek to determine and understand by measuring blood pressure several times during a single visit and again on successive visits, comparing readings to obtain an average. After the age of 40, systolic pressures of 140 or less are normal, pressures of 140 to 159 are considered borderline, and pressures exceeding 160 may signal an abnormality, especially if sustained over a period of time. At these ages, diastolic pressures under 90 are normal, pressures of 90 to 95 are borderline, and pressures greater than 95 are considered abnormal, indicating a need for further evaluation.

For the most part, psychological influences on blood pressure are transitory. Only rarely does psychological stress sustain an elevated pressure, the pressure usually dropping when the source of stress is removed. Excess salt, or sodium, is a more common cause of elevated pressure. Sodium apparently gets into arterioles, increases their contraction, and causes constriction.

Although the association is poorly understood, overweight also significantly contributes to high blood pressure. However, it is clear that when weight raises the blood pressure, reducing the weight also lowers the pressure.

Heredity is the principal contributor to the most common type of high blood pressure, known as essential or familial hypertension, which affects almost 90 percent of all people with excessive diastolic pressure. For this reason, a family history of high blood pressure is significant. This problem often first appears in middle life, but minor elevations in pressure during youth may give early clues. However, the mechanisms by which genes affect blood pressure are unknown.

Evaluation of high blood pressure usually includes a study of the kidneys because kidney disease is frequently associated with pressure problems. While this form of high pressure differs from essential hypertension, the essential type can damage the kidneys. In some cases it is difficult to determine whether high pressure preceded kidney disease, or vice versa.

In rare instances, mostly in young people, tumors of the adrenal gland cause high blood pressure. The possibility must be considered, but is usually quickly ruled out.

High Blood Pressure

High blood pressure by itself is not a serious problem. However, its secondary effects -- prolonged exposure of the heart, brain, kidneys, and blood vessels to high pressure -- are serious threats to well-being. Fortunately, harm can be minimized by lowering the blood pressure with drugs prescribed by a physician. But effective control requires full awareness of the condition and the aims of therapy. Because treatment may involve some side effects, the hypertensive must learn to deal with them. If necessary, the physician can usually modify the drug program to reduce troublesome reactions, so that therapy need not interfere with the normal enjoyment of life.

The term "blood pressure" refers to the pressure in the large arteries of the arms and legs. The measured pressure in millimeters of mercury is expressed in two numbers, the first always higher than the second. The first number is the peak (systolic) pressure reached when the heart muscles fully contract. When the heart relaxes, the pressure falls to a low point, the diastolic pressure, preceding the next heartbeat. This is indicated by the second number. Thus, a reading of 130/80 means a systolic pressure of 130 and a diastolic pressure of 80 millimeters of mercury.