February 9th, 2011
08:45 AM ET
Every weekday, a CNNHealth expert doctor answers a viewer question. On Wednesdays, it's Dr. Otis Brawley, chief medical officer at the American Cancer Society.
Question asked by Nate of Irvine, California:
What should you do if your blood pressure skyrockets from 130 to 159 and switches constantly?
Your question provides a great opportunity to review blood pressure issues. Hypertension is a common medical problem in the U.S. It is estimated that one-third of adults have hypertension. Many who have it are unaware that they have it.
Long-term, prolonged high blood pressure puts added stress on the heart and arteries. A person with years of uncontrolled high blood pressure often has an enlarged heart and thickened walls of the arteries. Prolonged uncontrolled hypertension can lead to stroke, congestive heart failure, kidney failure, blindness and other illnesses. Hypertension is commonly seen with diabetes in what is termed "metabolic syndrome." The combination can increase risk of stroke, heart failure, peripheral vascular disease, kidney failure and blindness.
Risk factors for hypertension include being overweight or obese, a sedentary lifestyle, a diet high in salt and excess alcohol intake. Some families also tend to have a history of hypertension, indicating that there is a genetic component as well as an environmental component.
Blood pressure is most commonly measured with a blood pressure cuff placed around the upper arm. It is given as two numbers that are the measure of the weight of a tube of mercury. The units are millimeters mercury or mmHg.
The higher number, or the systolic, is the pressure in the area measured when the heart beats or contracts, and the lower number, or diastolic, is the pressure when the heart relaxes after the heartbeat. Blood pressure changes throughout the day. When a person is exercising or under stress, it can go up. When someone is relaxing, it can go down. Similarly. blood pressure can vary when a person is lying in bed, sitting or standing. Most people occasionally feel a bit light-headed for a moment when they stand up. This is because of the blood pressure dropping when standing. Symptoms are relieved a few seconds later when the pressure rises to more normal levels.
Before 2003, hypertension was defined as a systolic blood pressure greater than 140 mmHg or a diastolic greater than 90mmHg. Studies have shown a group of people who really need goal pressure below this value, so in 2003, The Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure issued stricter definitions.
Averaging two or more properly measured readings at each of two or more visits, a normal blood pressure is a systolic less than 120 mmHg and a diastolic less than 80 mmHg. A category called "Pre-hypertension" is defined as a systolic of 120 to 139 mmHg or a diastolic of 80 to 89 mmHg.
Stage 1 or early hypertension is defined as a systolic of 140 to 159 mmHg or a diastolic of 90 to 99 mmHg. State 2 or more severe hypertension is a systolic greater than or equal to 160 or a diastolic of greater than or equal to 100 mmHg.
Malignant hypertension is defined as a diastolic blood pressure of 120 mmHg or having evidence of acute organ damage such as swelling in the back of the eye. These patients are usually treated to get the pressure down quickly. For asymptomatic patients who have no evidence of acute damage to the eyes, brain, heart or kidney, there is no proven benefit from rapid reduction in blood pressure. It may even be harmful.
Long-term effective treatment of hypertension can reduce a person's risk of a number of conditions. The treatment involves behavioral and diet changes as well as medications. This can take some time and patience.
I encourage you to work with your doctor and give the treatment time to show that it is working. Treatment is done in a stepped approach. The physicians will counsel exercise and dietary changes and especially reduction of salt intake. Then, there are initial oral blood pressure medicines. For those who do not have an acceptable response, or who have side effects, there are second- and third-level treatments. The process of finding a treatment can take some months. It is imperative that a regimen be found with which the patient is comfortable. Some form of high blood pressure treatment is likely to continue for the rest of the patient's life.
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Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.