By Daniel G. Graetzer, Ph.D.
Faculty Member, School of Health Sciences
High blood pressure (also known as hypertension) is a serious risk factor for cardiovascular disease, and it affects nearly 50% of U.S. adults at some point in their lives. According to the American Heart Association, hypertension is systolic/diastolic pressures that exceed 140/90 millimeters of mercury (mm Hg).
Systolic pressure is the peak force of circulating blood on artery walls, which occurs during contractions of the heart. Diastolic pressure is the lowest arterial pressure during the cardiac cycle and occurs between heartbeats.
Maintaining a blood pressure of less than 120/80 mm Hg is ideal; it allows the blood to efficiently deliver life-sustaining oxygen and nutrients to vital organs. However, when blood pressure remains higher than necessary for an extended period of time (high blood pressure), the workload of the heart is greatly increased. As a result, an individual with high blood pressure is at a greater risk of a heart attack, progressive heart failure, stroke, kidney diseases or diabetes.
In about 5-10% of cases, hypertension is due to a specific disease or physical problem (secondary hypertension). When the root cause of the problem is corrected, the blood pressure usually returns to normal.
In 90% of cases, however, health experts are unclear as to the exact cause of high blood pressure. Tragically, the first symptom of primary high blood pressure is often heart failure or stroke, and it is often labeled the “silent killer.”
Unlike a toothache or backache, high blood pressure can go undetected for years because there are generally no other symptoms. The only way to diagnose this health problem is to use a stethoscope and pressure cuff.
Nearly half of the people diagnosed with hypertension during routine screening are unaware that they have it. Although much more research needs to be done, most current theories hold that hypertension probably has several contributing influences, which can be subdivided into uncontrollable and controllable factors.
The Uncontrollable Factors of Hypertension
There are four uncontrollable factors of hypertension. They are:
- Heredity – A family history of high blood pressure is probably the most prevalent cause of hypertension. Patients whose parents or blood relatives have hypertension or have suffered strokes or heart attacks at an early age should be monitored regularly.
- Gender – Men are more likely to develop high blood pressure than women. However, a woman’s risk of high blood pressure increases greatly after menopause.
- Age – The older someone gets, the more likely that person is to develop high blood pressure. Hypertension is particularly common in persons over 65 with approximately 40% of the elderly having a systolic pressure over 160 mm Hg, a diastolic pressure over 90 mm Hg, or both. Hypertension in men generally begins between the ages of 35 and 50.
- Race – Black and Hispanic Americans have hypertension more than whites. Also, the hypertension tends to be more severe in these patients.
Controllable Factors of High Blood Pressure
There are five controllable factors for hypertension. They include:
- Body weight – Clinically obese individuals (more than 20% above their ideal body weight) are at risk of hypertension. Overweight people (less than 20% above ideal body weight) often have borderline high blood pressure.
- Sodium sensitivity – The typical American diet contains far more sodium than is necessary. Excessive sodium consumption can increase hypertension, so patients who are hypersensitive to sodium are often placed on salt-restricted diets.
- Alcohol consumption – Regular, heavy consumption of alcohol can increase blood pressure.
- Oral contraceptives – Women who take oral contraceptives often experience high blood pressure, and the risk of hypertension increases several times when women take oral contraceptives and smoke cigarettes. The danger of high blood pressure is further amplified when women taking oral contraceptives are overweight, have had high blood pressure during pregnancy, have a family history of hypertension, or have another medical condition such as kidney disease.
- Sedentary lifestyle – Regular exercise tends to relieve emotional stress and reduce body weight, while sedentary living contributes to obesity and hypertension.
Hypertension Is Treatable
In most cases, high blood pressure is treatable and can effectively be averted if hypertension is detected early and properly managed. Ideally, blood pressure should be monitored at every routine doctor’s visit in persons who have a normal blood pressure and about every 6 to 8 weeks in people with high blood pressure.
There are several ways to reduce hypertension as well. They include:
- Changing to a healthier diet – Reducing the consumption of foods rich in sodium, saturated fat, and cholesterol (red meat, fried foods) and increasing the consumption of fiber and complex carbohydrates (fruits, grains, vegetables, rice and pasta) can assist in the management of hypertension. When people reduce their total caloric intake and lose weight, their blood pressure can dramatically improve.
- Stopping excessive drinking – Alcohol abuse can have devastating effects on the cardiovascular system in addition to the liver and brain. Additionally, alcohol is a carbohydrate loaded with “empty” calories that reduces the effectiveness of a weight reduction diet.
- Stopping smoking – Chronic smoking has been shown to injure blood vessel walls and speed up hardening of the arteries. Smoking filtered cigarettes may decrease the risk of lung disease (bronchitis, emphysema or cancer), but it probably does not minimize the danger of cardiovascular problems. The risk of a heart attack in a person who once smoked and then quit is nearly the same as for a person who has never smoked.
- Following a regular exercise routine – The association between hypertension and exercise began to be investigated when research showed that distance runners had lower resting blood pressures than weightlifters. Consequently, regular, moderate-intensity aerobic activities are effective in lowering blood pressure in people with hypertension. However, blood pressure in hypertensive individuals can be lowered by about 5-25 mm Hg with exercise, but that exercise will generally not lower the blood pressure in people with a normal blood pressure.
Exercise Should Be Done at the Right Intensity
The American College of Sports Medicine recommends that individuals should exercise three to five times per week for 20 to 60 continuous minutes. Ideally, this exercise should be at 40-85% of the person’s maximum heart rate reserve to gain the health benefits of aerobic activity.
70% Exercise Heart Rate = ((220 – Your Age – Your Resting Heart Rate) x .70) + Resting Heart Rate)
Exercises that use large muscle groups, can be maintained continuously, and are rhythmical in nature (walking, jogging, running, cycling, swimming, or rowing) are most effective in reducing hypertension. Weight training (involving high-intensity dynamic or isometric muscle contractions) is generally less effective than endurance activities.
The common cliche “no pain – no gain” is poor advice for people with hypertension. Exercising too much too soon usually does more harm than good.
Treating High Blood Pressure with Medication
Drug therapy is recommended only when other lifestyle changes do not reduce high blood pressure to a safe level. Medications need to be individually prescribed by a physician and fall into these general categories:
- Diuretics – These medications reduce hypertension by washing out extra sodium from the body and reduce fluid retention.
- Sympathetic inhibitors – Beta-blockers and other similar drugs reduce the effects of adrenalin and nerve stimulation to the heart and blood vessels.
- Vasodilators – These drugs are more potent and are given to relax a patient’s blood vessels when there is no response to other medications.
- Enzyme inhibitors – These medications prevent the formation of hormones that activate the biochemical pathways that work to increase blood pressure.
- Sedatives or tranquilizers – These drugs are sometimes temporarily prescribed to people who are overly tense or have extreme type A personalities.
Drug therapy is much more effective when it’s used in combination with lifestyle modifications. Lifestyle modifications are preferable as a method of treating hypertension. Using drugs has a greater potential for abuse and addiction, may cause harmful side effects, and may expose patients to withdrawal symptoms after the medication is discontinued.