Part I – A Growing Epidemic
High blood pressure, also known as hypertension, is for the most part a preventable disease. The vast majority of cases are the consequence of diet and lifestyle choices over many years. Typically, symptoms appear only when the disease process is well advanced.
Currently about 73 million Americans, or one in three adults, have elevated blood pressure. In fact, persons over 50 years of age have a 90 percent chance of developing high blood pressure. Furthermore, it’s estimated that 65 percent of those with hypertension are not adequately controlled. From 1995 to 2005, the number of deaths attributable to elevated blood pressure rose by 56 percent according to data from the Centers for Disease Control and the National Heart, Lung and Blood Institute.
When high blood pressure goes untreated for years, irreparable damage may occur to organs such as the brain, eyes, heart, and kidneys. This greatly increases the risk of developing heart or kidney disease, having a stroke, becoming blind, or suffering other serious medical conditions. Hypertension is the largest single risk factor for cardiovascular (heart) disease mortality.
National health statistics illustrate the closely linked nature of the two disease syndromes. Heart disease is the leading cause of death for both men and women while hypertension is the strongest promoter for the development of cardiovascular disease. At the time of a first stroke, heart attack, or congestive heart failure, an average of 73 percent of the victims have elevated blood pressure.
Cardiovascular or heart disease describes a range of diseases that affect your heart. Three factors play primary roles in their formation: high blood pressure, high LDL (low-density lipoprotein) cholesterol, and smoking. Approximately half of American adults have one or more of these risk factors.
What is Hypertension?
Blood pressure is defined as the force of blood against the arteries. It rises and falls during the course of each day. It is highest in the morning and lowest during slumber at night. When it remains elevated over time, this is called high blood pressure or hypertension.
When blood pressure is checked, two values are recorded. The upper number reflects the highest pressure in the arteries when the heart contracts (systole). The lower number reflects the lowest arterial pressure during the resting phase or diastole which is reached just before the heart begins to contract again.
When blood pressure is high, there is a greater risk of complications. In most young people with high blood pressure, both systolic and diastolic pressures are high. In contrast, the majority of older people with hypertension have high systolic pressure with normal diastolic. Generally, systolic pressure increases with age, while diastolic increases until about age 55 and then declines.
For citizens of many developing countries, blood pressure does not increase with age and hypertension is practically nonexistent. This is due to a low salt intake and a high level of physical activity.
National Heart, Lung and Blood Institute Guidelines:
- Normal blood pressure: Below 120/80 millimeters mercury (mmHg)
- Pre-hypertension: Systolic pressure of 120-139 or diastolic pressure of 80-89
- Stage 1 hypertension: Systolic pressure of 140-159 or diastolic of 90-99
- Stage 2 hypertension: Systolic pressure above 160 or diastolic of 100 or higher
Although elevated blood pressure usually doesn’t cause any symptoms in the early stages, advanced hypertension can result in:
Damage to Body Systems
The heart is forced to work too hard when blood pressure stays elevated. When untreated over time, the heart enlarges and the chamber walls thicken. These thickened walls are less flexible and this further increases strain on the heart. These changes may lead to abnormal rhythms and even heart failure.
High blood pressure also causes thickening of the walls of blood vessels and promotes hardening of the arteries (atherosclerosis). These put people at risk of stroke, heart attack, and kidney failure.
Hypertension can narrow and thicken the blood vessels of the kidneys and render them less able to filter body fluids. Consequently, waste can build up in the blood and the kidneys may fail which will result in the need for dialysis or a kidney transplant.
A list of sources for this series of articles can be found here.