Hypertension – High Blood Pressure
To many people, the word hypertension suggests excessive tension, nervousness, or stress. In medical terms, hypertension refers to high blood pressure, regardless of the cause. Because it usually does not cause symptoms for many years until a vital organ is damage – it has been called “the silent killer”. Uncontrolled high blood pressure increases the risk of problems such as stroke, aneurysm, heart failure, heart attack, and kidney damage.
More than 65 million Americans are estimated to have high blood pressure. High blood pressure occurs more often in blacks – in 32% of black adults compare with 23% of white and 23% of Mexican Americans. It also occurs with high frequency in people whose ancestors are from China or Japan. The consequences of high blood pressure are worse for blacks. High blood pressure occurs more often in older people – in about three fourths of women compared with only about one fourth of people aged 20 to 74. People who have normal blood pressure at age 55 have a 90% risk of developing high blood pressure. High blood pressure is twice as common among people who are obese as among those who are not.
In the United States, only an estimated 70% of people with high blood pressure have been diagnosed. Of people with a diagnosis of high blood pressure, about 84% receive treatment, and of the people receiving treatment, about 58% have adequately controlled blood pressure.
When blood pressure is checked, two values are recorded. The higher value reflects the higher pressure in the arteries, which is reached when the heart contracts (during systole). The lower value reflects the lower pressure in the arteries, which is reached just before the heart begins to contract again (during diastole
Causes Of High Blood Pressure
Primary hypertension: High blood pressure with no known cause is called primary (formerly called essential) hypertension. Between 85% and 95% 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 in inherited abnormality affecting the constriction of arterioles, which help control blood pressure. Other changes may contribute to increase in blood pressure, including accumulation of excessive amounts of salt inside cells and decreased production of substances that dilate arterioles.
Secondary Hypertension: High blood pressure with a known cause is called secondary hypertension. Between 5% and 15% 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 from inflammation or other disorders may impair their ability to remove enough salt and water from the body, increasing blood volume and blood pressure. Other kidney disorders that cause high blood pressure include renal artery stenosis (narrowing of the artery supplying one salt 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. 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 enough to be diagnosed as high blood pressure in someone who has normal blood pressure at other times. In susceptible people, these belief increases in blood pressure are thought to cause damage that eventually results in permanent high blood pressure, even when no stress is present. This theory has not been proved.
Symptoms Of High Blood Pressure
In most people, high blood pressure causes no symptoms, despite the coincidental occurrence of certain symptoms that are widely, but erroneously, attributed to blood pressure: headaches, nose bleeds, dizziness, flushed face, and fatigue. People with high blood pressure may have these symptoms, but the symptoms occur just as frequently in people with normal blood pressure.
Treatment Of High Blood Pressure
Primary hypertension cannot be cured, but it can be controlled to prevent complications. Because high blood pressure itself has not symptoms, doctors try to avoid treatments that cause side effects or interfere with a person’s lifestyle. Alternative measures are usually tried before any drugs are prescribed. However, during therapy is usually started at the same time as alternative measures in all people with blood pressure at or above 160/100 mm Hg and in people with blood pressure at or above 120/80 mm Hg who also have diabetes, a kidney disorder, evidence of damage to a vital organ, or other risk factors for coronary artery disease.
Overweight people with high blood pressure are advised to lose weight. Losing as few as 10 pounds (4.5 kilograms), can lower blood pressure. For people who are obese or who have diabetes or high cholesterol levels, changes in diet (to a diet rich in fruits, vegetables and low-fat dairy products, with reduced saturated and total fat content) are important for reducing the risk of heart and blood vessel disease. Smokers should stop smoking.
Reducing the intake of alcohol and sodium (while maintaining and adequate intake of calcium, magnesium, and potassium) may make drug therapy for high blood pressure unnecessary. Daily alcohol intake should be reduced to no more than 2 drinks (a daily total of 24 ounces about 1 liter of beer, 8 ounces about 240 milliliters of wine, or 2 ounces about 60 milliliters of 100-proof whiskey or other liquor) in men and 1 drink in women. Daily sodium intake should be reduced to less than 2 and a half grams, or sodium chloride intake, to 6 grams.
Moderate aerobic exercise is helpful. People with primary hypertension do not have to restrict their physical activity as long as their blood pressure is controlled. Regular exercise helps reduce blood pressure and weight and improves the functioning of the heart and overall health.
Doctors often recommend that people with high blood pressure monitor their own blood pressure at home. Self-monitoring probably helps motivate people to follow a doctor’s recommendations regarding treatment.