Complications of Hypertension
High blood pressure or hypertension can lead to several complications. Uncontrolled hypertension results in increased pressure in the artery walls (both small and large arteries are affected) which can damage vital organs. The organs most often affected by hypertension include the heart, brain, kidneys and eyes. Hypertension accelerates a condition known as atherosclerosis. Atherosclerosis occurs when fatty substances or plaques build up in the inner lining of the arteries causing them to harden and thicken. The presence of plaques may reduce the blood flow through the arteries. Reduction of blood flow in an artery that leads to the brain may result in a transient ischemic attack, a mini stroke in which symptoms usually subside within five to twenty minutes.
Rupture of a plaque may result in the formation of blood clots which may result in blockage of a blood vessel or may be disseminated to other parts of the body. A blood clot occurring in a plaque containing artery supplying the brain may result in an ischemic stroke. Complete blockade of a coronary artery (the coronary arteries carry blood to the heart) by a blood clot results in a heart attack. Similarly, atherosclerosis in the coronary arteries can result in a type of chest pain known as angina, occurring especially when the blood flow through the arteries is insufficient.
Uncontrolled hypertension may result in a bulge in the aorta (aortic aneurysm) or in any large artery. The bulge results from weakening of the arterial wall brought about by fatty deposits. Aneurysms may also occur in the chest (thoracic aneurysm), in the abdomen below the kidneys (abdominal aneurysm) and in the brain. Aneurysms are dangerous as they may rupture.
Rupture of an aneurysm in an artery supplying blood to the brain results in a hemorrhagic stroke, a condition which is potentially fatal. In general hypertension increases the risk of stroke by 4-6 times.
Increased pressure in the blood vessels makes the heart work harder to pump blood. Over time this excess workload thickens and increases the size of the hearts left chamber (known as the ventricle) resulting in condition known as left ventricular hypertrophy. Left ventricular increases the risk for angina, heart attack, heart failure and cardiac arrest. Left ventricular hypertrophy may eventually result in a weakening of the heart muscle walls resulting in the heart not being able to pump blood as strongly as necessary (left-sided heart failure). The kidneys respond by retaining salt and water further worsening the hypertension and resulting in build-up of fluid (congestion) in the organs, feet, legs, ankles, and arms; a condition known as congestive heart failure.
Uncontrolled hypertension may result in atherosclerotic weakening and narrowing of the main arteries supplying the kidneys; the small arteries within the kidneys may also be affected resulting in inability of the kidneys to remove waste products, and eventually in kidney failure. Hypertension is the second most common cause of kidney failure after diabetes.
Hypertension may cause narrowing, thickening or tearing of the tiny arteries that supply blood to the part of the eye known as the retina, a condition known as hypertensive retinopathy. This condition may lead to headaches, problems with eyesight and even blindness. Hypertensive retinopathy usually evolves gradually and many years may pass between a diagnosis of hypertension and when eye symptoms manifest.
Uncontrolled hypertension has been associated with cognitive decline and senile dementia. It also affects the ability of affected individuals to think, remember and learn. In general, avoidance of risk factors, dietary modifications and appropriate treatment help in reducing blood pressure and preventing complications from hypertension.