If other factors remain constant, blood flow increases as arterial blood pressure increases. The organs of people with hypertension are thus adequately perfused with blood until the excessively high pressure causes vascular damage. Because most patients are asymptomatic (without symptoms) until substantial vascular damage has occurred, hypertension is often referred to as a silent killer.
Hypertension is dangerous for a number of reasons. First, high arterial pressure increases the afterload, making it more difficult for the ventricles to eject blood. The heart, then, must work harder, which can result in pathological changes in heart structure and function, leading to congestive heart failure. Additionally, high pressure may damage cerebral blood vessels, leading to cerebrovascular accident, or "stroke." (Stroke is the third-leading cause of death in the United States.) Finally, hypertension contributes to the development of atherosclerosis, which can itself lead to heart disease and stroke as previously described.
PtW Preeclampsia is a toxemia of late pregnancy characterized by high blood pressure, proteinuria (the pres__I ^ ence of proteins in the urine), and edema. For reasons discussed in chapter I 7, only negligible amounts of proteins are normally found in urine, and the excretion of plasma proteins in the urine can cause edema. In preeclampsia, the sensitivity of blood vessels to pressor agents (which cause vasoconstriction) is increased, resulting in decreased organ perfusion and increased blood pressure. The danger of preeclampsia is that it can quickly degenerate into a state called eclampsia, in which seizures occur. This can be life-threatening, and so the woman with preeclampsia is immediately treated for her symptoms and the fetus is delivered as quickly as possible.
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Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...