Hypertension: The Silent Killer

Excerpted from
The DASH Diet for Hypertension
By Thomas Moore, M.D.

An astounding one in four adult Americans suffers from hypertension - 50 million of our citizens in all. The presence of this condition is even more widespread among older Americans, more than half of whom have hypertension. Despite its prevalence, hypertension is seriously underestimated. To understand how deadly this disease is, just consider that it is a prime risk factor for both heart disease and stroke, the first and third leading causes of death in this country, and is responsible for one-quarter of all cases of kidney failure in the United States. High blood pressure can also cause other life-threatening problems. Bottom line: If you have hypertension, you need to deal with it, or it may kill you.

Before we go any further, a word about terminology. The two terms hypertension and high blood pressure can be used interchangeably, although we use high blood pressure much more often.

A Deadly Disease That Affects Millions

About 50 million Americans suffer from hypertension. Medicine has made a lot of progress in the fight against this disease, but we are a long way from where we need to be. Consider these statistics on conditions that are caused by high blood pressure:

• Stroke rates are up slightly since 1993.

• The society-wide improvement in heart disease is slowing.

• The prevalence of kidney failure requiring dialysis or transplantation is increasing.

• The prevalence of congestive heart failure is increasing.

If you have hypertension, you do not experience pain or other noticeable symptoms for many years. The only way you can tell you have hypertension is to be tested for it. About one-third of people with high blood pressure don't even know they have it and therefore do not seek treatment. Even those who do get attention for their high blood pressure frequently discontinue treatment because it doesn't make them feel any better. Only half of those people with hypertension are taking medication, and only about a quarter have their high blood pressure under control.

However, if untreated, hypertension can lead to a host of serious and possibly life-threatening medical problems. Seemingly benign and yet so deadly, hypertension has been called the silent killer.

What Is High Blood Pressure/Hypertension?

Each time your heart beats, it pumps out blood through your arteries. "Blood pressure" is the force of the blood pushing against the walls of your arteries, which deliver blood throughout your body.

Your blood pressure is at its greatest when the heart contracts to pump out blood. This is called systolic pressure. Your blood pressure falls when the heart is at rest between beats. This is called diastolic pressure.

Different activities make your blood pressure go up or down. For example, running to catch the bus will increase your blood pressure. On the other hand, when you're asleep, your blood pressure is relatively low. Such changes in blood pressure are normal.

Some people have blood pressure that is high all or most of the time. Their blood constantly pushes against the walls of their arteries with higher than normal force. These people have a condition called hypertension. High blood pressure is dangerous because it makes your heart work harder and damages your blood vessels.

What Causes High Blood Pressure?

The majority of people who have hypertension are predisposed to the disease because it runs in their family. However, some people who are not predisposed to hypertension may develop the disease simply because of poor diet and lifestyle.

Truth and Consequences

Although high blood pressure usually has no noticeable symptoms, the consequences are deadly serious and include the following:

Arteriosclerosis ("hardening of the arteries"): High blood pressure harms the arteries by making them thick and stiff. This accelerates the buildup of cholesterol and fats in the blood vessels, which clog the vessels like rust in a pipe. This in turn prevents the blood from flowing through the body and in time can lead to heart attack or stroke.

Heart attack: Blood carries oxygen to the body. When the arteries that bring blood to the heart become blocked, the heart muscle does not get enough oxygen. Reduced blood flow can cause chest pain (angina). Eventually the flow may be stopped completely, causing a portion of heart muscle to suffer irreversible injury-or heart attack.

Stroke: A stroke is a "brain attack." When high blood pressure narrows the blood vessels to the brain, less blood can get to the brain. If one of the narrowed arteries gets blocked completely, the part of the brain fed by that artery doesn't get enough oxygen and nourishment, and a stroke (thrombotic stroke) may occur. A stroke can also occur when very high pressure causes a break in a weakened blood vessel in the brain (hemorrhagic stroke).

Enlarged heart: High blood pressure causes the heart to work harder. Over time this causes the heart to thicken and stretch. Eventually the heart fails to pump normally, causing fluids to back up into the lungs, a condition called congestive heart failure.

Kidney damage: The kidney acts as a filter to rid the body of extra fluid and wastes. Over a number of years, high blood pressure can narrow and thicken the blood vessels of the kidney. When this happens, the kidney filters less fluid, and waste builds up in the blood. The kidneys may fail altogether. When this happens, medical treatment (dialysis) or a kidney transplant may be needed.

Controlling high blood pressure can prevent all these conditions from developing.

How High Blood Pressure Is Treated

If you have mild hypertension, you may be able to bring your blood pressure into the healthy range by cutting down on salty foods, exercising and losing weight, and drinking alcohol in moderation. But sticking with these measures can be a challenge, and most people require medications to be successful in lowering blood pressure. For moderate and severe high blood pressure, antihypertensive medications are almost always required. While effective, these drugs can be expensive and may have unpleasant side effects, such as fatigue, weakness, light-headedness, headache, digestive problems, and sexual dysfunction.

What has been missing is an approach to treating hypertension that is simple, safe, and effective. Some of us have long believed there is such a way to treat hypertension. We think an important factor affecting blood pressure has been neglected during the quest for hypertension treatments and that, if it were properly looked into, a breakthrough in treating hypertension would be possible.

What is that factor? It is, quite simply, the proper diet. Specifically, certain foods, when eaten in the right amounts and combinations, have the ability to lower blood pressure significant!)'. These foods are the focus of the DASH diet.