heart and blood vessel disorders
High Blood Pressure
Causes of High Blood Pressure
High blood pressure may be Primary Secondary High blood pressure with no known cause is called primary (formerly called essential) hypertension. About 85% of people with high blood pressure have primary hypertension. Several changes in the heart and blood vessels probably combine to increase blood pressure. For instance, the amount of blood pumped per minute (cardiac output) may be increased, and the resistance to blood flow may be increased because blood vessels are constricted. Blood volume may be increased also. The reasons for such changes are not fully understood but appear to involve an inherited abnormality affecting the constriction of arterioles, which help control blood pressure. Other changes may contribute to increases in blood pressure, including accumulation of excessive amounts of sodium inside cells and decreased production of substances that dilate arterioles. High blood pressure with a known cause is called secondary hypertension. About15% of people with high blood pressure have secondary hypertension. In many of these people,high blood pressure results from A kidney disorder Many kidney disorders can cause high blood pressure because the kidneys are important in controlling blood pressure. For example, damage to the kidneys resulting from inflammation or other disorders may impair their ability to remove enough sodium and water from the body, increasing blood volume and blood pressure. Other kidney disorders that cause high blood pressure include Blockage of the Renal Arteries (narrowing of the artery supplying one of the kidneys), which may be due to In other people,secondary hypertension is caused by another disorder, such as Hormonal disorders Use of certain drugs that cause high blood pressure include Hyperaldosteronism (overproduction of aldosterone, often by a noncancerous tumor in one of the adrenal glands), Substancesthat can cause or worsen high blood pressure include alcohol (excessive use), stimulants (eg amphetamines,cocaine), medications such as corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), oral contraceptives (birth control pills), sympathomimetics (certain decongestants in cold remedies, such aspseudoephedrineandphenylephrine), and licorice. Arteriosclerosis interferes with the body's control of blood pressure, increasing the risk of high blood pressure. Arteriosclerosis makes arteries stiff, preventing the dilation that would otherwise return blood pressure to normal. Other disorders that may cause high blood pressure include Coarctation of the Aorta , Obesity , a sedentary lifestyle, stress, smoking, and excessive amounts of alcohol or sodium in the diet all can play a role in the development of high blood pressure in people who have an inherited tendency to develop it. Additionally, Stress tends to cause blood pressure to increase temporarily, but blood pressure usually returns to normal once the stress is over. An example is "white coat hypertension," in which the stress of visiting a doctor's office causes blood pressure to increase to a level considered elevated or even high blood pressure. These temporary increases are one of the reasons why doctors now measure blood pressure several times on several different visits before making the diagnosis of high blood pressure. One high reading out of several may be due to stress, but if blood pressure is consistently high it is unwise to chalk it up to stress. Overview of Anxiety Disorders can also cause high blood pressure, and doctors can determine whether treatment for anxiety is appropriate, which may in turn lower the person's blood pressure. 