According to the U.S.. Centers for Disease Control and Prevention, 32 percent of all Americans 20 years of age and older have been diagnosed with hypertension as of 2006. This has resulted in a total of 40.5 million visits to doctors' offices, emergency departments and hospital clinics in that year alone. It also caused 23,855 deaths. As these statistics demonstrate, hypertension is a serious condition. The systems that are affected the most are the brain, eyes, heart and kidneys.
Brain
Elizabeth Corwin, PhD writes in "Handbook of Pathophysiology," that having hypertension for a considerable period of time heightens the risk of developing a stroke. There are two types of strokes: hemorrhagic strokes and ischemic strokes. In hemorrhagic strokes, the high pressure within a blood vessel in your brain causes that vessel to rupture causing a hemorrhage within your brain. On the other hand, in ischemic strokes, you have a clot which interferes with the flow of blood starving the brain of oxygen.
Eyes
Hypertension causes the blood vessels in your eyes to narrow. This makes it harder for blood to flow through them and leads to the development of areas of ischemia. These ischemic areas look fluffy white, and it is this appearance which gives them the nickname of "cotton-wool" spots. But, as written by Paul Riordan-Eva, M.D., in "Current Medical Diagnosis & Treatment," hypertension also causes hemorrhages within the retina and it destroys capillaries. In addition, the increased pressure within the retinal veins makes those veins press down on the arteries, causing what is referred to as "arteriovenous nicking."
Heart
According to Elizabeth Corwin, PhD in "Handbook of Pathophysiology," if your coronary artery has become narrow, then the heart will not receive the oxygen that it needs. This will cause a heart attack, or myocardial infarction (MI). In chronic hypertension, the left ventricle (chamber of the heart) will be enlarged. Due to its increased size, it needs even more oxygen and with the narrowed arteries, its increased need will not be supplied. This will also lead to an MI.
Kidneys
Ramzi Cotran, M.D., explains in "Robbins Pathologic Basis of Disease," that hypertension narrows the arteries within the kidneys because the walls of the renal arteries get thicker due to a substance called hyaline. Similar to the disorder in your eyes, you can also develop small hemorrhages in your kidneys. These multiple hemorrhages give the kidneys a "flea-bitten" look. As the damage progresses, your kidneys will not be able to do their job of filtering. You will lose protein into your urine (called proteinuria) and will eventually have blood in your urine (hematuria) as well.
References
- U.S. Centers for Disease Control and Prevention: Hypertension
- "Current Medical Diagnosis & Treatment 2009"; Stephen McPhee, M.D., Maxine Papadakis, M.D.; 2009
- "Handbook of Pathophysiology"; Elizabeth Corwin, MSN, PhD, FNP; 2000
- "Robbins Pathologic Basis of Disease"; Ramzi Cotran, M.D., Vinay Kumar, M.D., Stanley Robbins, M.D.; 1994
