What're the complications of high blood pressure?
Over time, high blood pressure can cause problems in other parts of the body because of the damage to the blood vessels.
Blood vessels can narrow due to high blood pressure and the accumulation of cholesterol. Blockage of arteries in the brain can lead to stroke. About two-thirds of people who suffer a first stroke have moderate elevated blood pressure (160/95 mm Hg or above). Hypertensive people have up to ten times the normal risk of stroke, depending on the severity of the blood pressure. Hypertension is also an important cause of so-called silent cerebral infarcts, which are blockages in the blood vessels in the brain that may predict major stroke or progression to dementia over time.
Blockage of blood vessels in the kidneys can lead to kidney failure. Over time, uncontrolled high blood pressure can result in narrowing of the arteries supplying the kidneys. High blood pressure also damages the kidneys directly and may lead to kidney failure. Kidney damage, in turn, raises blood pressure even more. High blood pressure causes 30% of all cases of end-stage kidney disease (medically referred to as end-stage renal disease or ESRD). Only diabetes leads to more cases of kidney failure. In fact, although antihypertensive therapy has reduced the incidence of stroke and heart attack, the incidence in ESRD has almost doubled in the last decade.
High blood pressure is the major risk factor for heart disease. High blood pressure puts extra wear and tear on the heart, and can lead to heart failure. Hypertension precedes congestive heart failure in between 75% and 90% of heart failure cases. To compensate for increased blood pressure, the heart must work harder to pump blood, and so its muscles thicken (called hypertrophy), usually in the left side (called left-ventricle dysfunction). These thickened muscles pump inefficiently, and over time, the force of their contractions weakens. The heart muscles then have difficulty relaxing and filling the heart with blood. The heart begins to fail. The failing heart then triggers a number of hormonal and neurochemical mechanisms to correct imbalances in blood pressure and flow. This response, called remodeling, is helpful in the short run but very destructive and irreversible over time. About half of people who suffer their first heart attack have moderate (160/95 mm Hg) over above hypertension. High blood pressure increases the risk for a heart attack by up to five times, depending on the severity of the hypertension.
Sexual dysfunction is more common and more severe in men with hypertension, and particularly in smokers, than it is in the general population. Many of the drugs used to treat hypertension are thought to cause impotence as a side effect; in these cases, it is reversible when the drugs are stopped. More recent evidence is suggesting, however, that the disease process that causes hypertension itself is the major cause of erectile dysfunction in these men.
Hypertension also increases the elimination of calcium in urine that may lead to loss of bone mineral density, a significant risk factor for fractures, particularly in elderly women. In one study of Englishwomen, those with the highest blood pressure lost bone density at nearly twice the rate of those in the lowest range.
High blood pressure causes the arteries to become hard and inelastic, a condition often referred to as "hardening of the arteries." This condition prevents blood from flowing through the body effectively and can lead to heart attack and stroke.
High blood pressure can injure the eyes, causing a condition called retinopathy. Blockage of blood vessels in the eye can cause impaired vision or even blindness.
High blood pressure can cause the blood vessels to widen. When this occurs in the brain or the aorta, death can result.