Hypertension (High Blood Pressure)

Hypertension, or high blood pressure, occurs when too much pressure builds up in the blood vessels. Hypertension is a factor in many debilitating and fatal health conditions, but high blood pressure itself has no symptoms.

 

One third of US adults (approximately 6.5 million Americans) have high blood pressure, but at least a third of this number are unaware that they have hypertension and are doing nothing to lower their blood pressure.

Blood vessels are flexible: They contract and widen depending on the body's needs. If blood vessels narrow, pressure within the blood vessels increases, as it becomes more difficult for blood to flow. If blood vessels are chronically narrow, hypertension results.

In 90 to 95 percent of high blood pressure cases, no definitive cause can be found. When a cause is found, high blood pressure is usually due to abnormalities in the aorta, kidney problems or abnormal narrowing in certain blood vessels.

While pinpointing a cause for hypertension is not always possible, many hypertension risk factors are well known. Age, ethnicity and family history are risk factors that cannot be controlled. High blood pressure usually develops in men between the ages of 35 and 55, and in women after menopause.

The risk of hypertension is highest among African-Americans. They have an earlier than usual age of onset, a higher incidence rate and a higher rate of health complications.

Controllable risk factors for high blood pressure include:

High blood pressure is known as the "silent killer" due to its lack of symptoms. Hypertension increases the risk of serious health complications, including strokes, heart attacks, heart failure, kidney failure, aneurysms and vision problems (including blindness).

The risk of strokes or heart conditions increases dramatically if high blood pressure is combined with other risk factors, such as obesity, smoking or diabetes.

Blood pressure readings are the only way to diagnose high blood pressure. Hypertension is diagnosed if blood pressure readings are consistently greater than 140/90 mm Hg. As blood pressure varies depending on the time of day and circumstances, several blood pressure readings are taken on different days at different times to diagnose hypertension.

While hypertension medications are available, lifestyle changes are the first line of treatment. Maintaining a healthy weight, quitting smoking, staying active and eating a heart-healthy diet are often enough to control high blood pressure.

If lifestyle changes alone cannot reduce hypertension, several different high blood pressure medications are available:

ACE Inhibitors: This hypertension medication blocks the action of angiotensin II. Angiotensin II causes blood vessels to narrow, so it is often a factor in high blood pressure.

Beta Blockers: Beta blockers slow the heart rate so that blood is not forced as rapidly through the blood vessels, resulting in lower blood pressure.

Calcium Channel Blockers: Calcium channel blockers prevent calcium from accumulating in heart and blood vessels. With less calcium, blood vessels relax, widening the channels for blood flow and relieving the pressure.

Diuretics: The mainstay of hypertension medications, diuretics have proven more effective than newer high blood pressure medications in recent studies. Diuretics remove excess water and salt from the body. This reduces fluid in the blood vessels, causing a drop in blood pressure.

Resources

American Heart Association. (nd). Factors that contribute to high blood pressure.

American Heart Association. (nd). High blood pressure.

American Heart Association. (2004). Mental function declines when blood pressure rises in young adults.

American Heart Association. (nd). What causes high blood pressure?

National Heart, Lung, and Blood Institute. (2005).allhat study findings for racial sub-groups show diuretics work better than newer medicines for high blood pressure.

National Heart, Lung, and Blood Institute. (2003). NHLBI study finds all-in-one approach to lifestyle changes effectively lowers blood pressure.

National Heart, Lung, and Blood Institute. (nd). What is high blood pressure?