HYPERTENSION

Hypertension, or high blood pressure, is an abnormal elevation of the blood pressure. The blood pressure is measured with a sphygmomanometer, or blood pressure cuff. Two readings are obtained: The systolic pressure and the diastolic pressure. With every heartbeat the blood pressure changes. When the heart is fully contracted, the blood pressure is at its highest, or systolic pressure. When the heart is relaxing and filling with blood, the blood pressure is at its lowest, or diastolic pressure. Blood pressure is recorded as systolic pressure/diastolic pressure, for example 120/80 mm. mercury. The exact level at which a person's blood pressure becomes abnormally high is somewhat arbitrary. The reason for this is that there is a continuous relationship between blood pressure elevation and the risk of heart disease, stroke, kidney disease, etc. For every slight increase in blood pressure, there is a corresponding slight rise in the risk of developing these complications(It is not a stepwise or all or none relationship. That is, even though doctors consider blood pressures above 140/90 mm. mercury as abnormal, if your blood pressure is 138/86, it doesn't mean that you are free of risk for developing complications from high blood pressure.) What this does mean is that the lower your blood pressure, the better off you are(the less likely you are to develop heart disease, kidney disease, etc.), as long as you have no symptoms from low blood pressure per se. Unfortunately, high blood pressure is a medical illness that often has no warning signs until it is too late--when the heart attack or stroke actually occurs. In fact, many times people who are feeling well(and have hypertension) feel worse when started on blood pressure lowering medicines. Sometimes these symptoms are a direct result of the medicines, and sometimes the symptoms occur because the blood pressure came down substantially over a short period of time. If the symptoms(such as fatigue, weakness, tiredness) are simply related to the fact that the blood pressure dropped they oftentimes subside after a month or two.

 

WHEN DOES A PERSON HAVE HYPERTENSION?

Blood pressures of 140/90 or greater are high enough to require treatment. In some cases, people benefit from treatment even if their blood pressure is not that high. Approximately 25% of adults in the United States have blood pressures exceeding 140/90. Many of these people have isolated systolic hypertension. However, even isolated systolic hypertension is associated with a risk of stroke and heart disease. Hypertension does tend to run in families and is related to the daily intake of salt in the diet.

 

WHAT COMPLICATIONS RESULT FROM UNCONTROLLED HYPERTENSION?

Hypertension that is ignored or not properly controlled increases the risk of stroke(7 times normal), congestive heart failure(6 times normal), heart attack(3 times normal), hardening of the arteries(atherosclerosis), heart enlargement, kidney failure, rupture of blood vessels, eye disease and possibly blindness. Good control of high blood pressure can essentially eliminate the increased risk of developing all these complications. However, many people don't understand that most forms of hypertension require treatment indefinitely. Stopping treatment for hypertension will allow the blood pressure to return to its previous high levels and again increase the risk of developing problems related to the blood pressure.

 

 

WHAT CAUSES HYPERTENSION?

Although hypertension can be caused by a number of different conditions, more than 9 out of 10 people have "essential hypertension", in which the causative agent or mechanism is unknown. Current beliefs are that a number of different factors predispose to this abnormality. These factors include a family history of high blood pressure (i.e. genetics), male sex, black race, weight 20% or greater above the recommended body weight, heavy alcohol consumption, oral contraceptives, smoking, and sedentary lifestyle. Also, increased "nervous energy" such as that seen in stress, changes in the way the kidneys handle extra salt in the diet and changes in kidney related hormone levels predispose to hypertension. In the 10% of cases in which a specific cause for the hypertension can be found, the underlying problem may be any of a number of kidney diseases, adrenal or thyroid glandular problems, medications, certain kinds of heart problems or vascular diseases. It is sometimes important that these causes of hypertension be identified, as the hypertension can be cured if the underlying problem is effectively treated.

 

HOW IS HYPERTENSION DIAGNOSED?

Hypertension is diagnosed when the blood pressure measured in the arm is repeatedly elevated. Many people have labile hypertension, in which they tend to have high blood pressure when under stress but not necessarily at other times. Remember, blood pressure levels can change with every beat of the heart. The stress of being in a doctor's office can often raise blood pressure. But it is also true that if that stress can raise the blood pressure, then other stresses throughout the day can, and typically do, also raise the blood pressure. High blood pressure, even if it is intermittent, should be treated. The key question in diagnosing hypertension is whether the blood pressure is repeatedly elevated.

 

HOW IS HYPERTENSION TREATED?

Everyone with hypertension should invest in a blood pressure cuff and learn to take his or her own blood pressure at home. There is no other way to tell how high the blood pressure is and how well the treatment for the hypertension is working. If a specific cause of the hypertension is discovered, treatment of this oftentimes will cure the hypertension. Most often, the cause of the hypertension is not known--that is, a diagnosis of "essential hypertension" is made. The cornerstones of essential hypertension management are dietary salt restriction, weight reduction if you are overweight, and regular exercise. The average salt intake in the United States is 9 to 12 grams of salt per day per person. If the salt intake of a hypertensive person is reduced to less than 5 grams of salt per day, on average the blood pressure will drop 10-15 mm. of mercury. It is also known that on average, a 25 pound weight loss will decrease the systolic blood pressure by 10 mm of mercury. Exercise and conditioning also probably have significant impacts on lowering blood pressure, particularly in stressed, anxious or poorly conditioned individuals. Thus, a combination of simple approaches effectively practiced could control a lot of hypertension. But lifestyles are hard to change.

 

If the above measures fail, the next step is the use of various drugs. Usually a person is begun on 1 or 2 drugs, and then the dose is increased and or other drugs are added to bring the blood pressure down to an acceptable range. Diuretics are sometimes used to treat hypertension. They work by washing excess salt and water out of the body through the kidneys. They thereby reduce the circulating blood volume, and with a smaller circulating blood volume the blood pressure falls. Unfortunately, the effects of most of the milder diuretics can be neutralized by a person simply increasing his salt intake(and thereby water intake). Therefore, salt restriction remains an important measure even when using these drugs. Other drugs used to treat hypertension include those that act on the nervous system to decrease nervous stimulation of the heart and blood vessel system, those that work directly on the heart to decrease the work that it does and thereby the blood pressure, those that work directly on blood vessels, and those that affect various hormone levels and kidney function. One important group of these drugs are called B(beta)-blockers(Inderal, Tenormin, Corgard, Blocadren, Lopressor). They decrease the heart rate and the vigor of the heart's contraction. Thus, if the heart pumps less vigorously, the blood pressure will be lower. By pumping less vigorously(and therefore pumping against a lower head of pressure) the heart does not have to work as hard and therefore is benefited from this medication. Likewise, abrupt withdrawal of this medicine will abruptly increase the work load on the heart and therefore serious problems(even a heart attack) can result. Thus, these medicines should not be abruptly stopped and one should not run out of them. Another group of these drugs are called calcium channel blockers(Calan, Cardizem, Procardia), and act by relaxing blood vessels and decreasing the work load of the heart. Another group of these drugs are called angiotensin converting enzyme inhibitors(Capoten, Vasotec, Prinivil, Zestril, Lotensin), and act by blocking a hormone system that causes blood vessel constriction and salt retention. Another group of these drugs are called vasodilators(Apresoline, Minipres), and act by relaxing blood vessels.

 

It cannot be overstaqted that medications are not THE solution to health problems.  Wouldn't it be wonderful if we could just pop a pill once a day, and then just do whatever we want the rest of the day, and live forever!  That's just magical thinking.  Too many individuals use that type of thinking about medications they take for high blood pressure, diabetes and other chronic diseases.  As stated above, if you take a diuretic for hypertension and don't watch your salt intake, you will cancel out the benefits of taking it.  The same goes for other medications.  You have to become part of the solution to your health problems.  You have to do your part to succeed with the minimal use of medications at the minimal cost.

 

All medicines, whatever they are, have unwanted side effects. Most of the time these side effects are mild, but occasionally they can be serious. These side effects can range from tiredness to gastrointestinal upset to loss of sexual desire/potency to depression. If you have problems with your medicines, let your doctor know this. The medicines you are given for control of high blood pressure are being given to you because the potential risks of taking them are outweighed by the benefits they will bestow upon you by lowering your blood pressure. But your doctor does need to know all the facts to make good judgments. Your blood pressure and the effects of these medicines need to be periodically monitored by your doctor. Remember, by controlling your blood pressure you can eliminate its potentially adverse consequences and lead an otherwise normal life.

 

Revised 8/08
 


 

 

ŠTed A. Tobey, M.D., Inc. ~ All Rights Reserved