Blood Pressure - June 1, 2010 Newsletter

High Blood Pressure

EHE Newsletter, Volume 10, Number 22
June 1, 2010

Approximately 74.5 million people in the United States have high blood pressure — a condition that typically develops over many years and eventually affects nearly everyone. According to the Centers for Disease Control and Prevention (CDC), almost 90 percent of adults aged 45 to 64 years will develop high blood pressure during the remainder of their lifetimes. High blood pressure is a major risk factor for heart disease, stroke, congestive heart failure and kidney disease.

What is High Blood Pressure?

Blood pressure refers to the pressure that blood applies to the inner walls of the arteries. The heart pumps blood into the arteries which carry the blood throughout the body. High blood pressure — also called "hypertension" — indicates that the pressure in the arteries is above the normal range.

An individual’s blood pressure is defined by two measurements:

Systolic pressure measures the pressure in the arteries when the heart beats and fills them with blood.
Diastolic pressure measures the pressure in the arteries when the heart is at rest between beats.

Blood pressure is reported as systolic pressure over diastolic pressure — for example, 120/80 mmHg. The "mmHg" stands for "millimeters of mercury," the units used to measure blood pressure.

According to the National Heart, Lung and Blood Institute (NHLBI), blood pressure measurements are divided into the following categories:

Normal: Systolic pressure is less than 120 AND diastolic pressure is less than 80.
Pre–hypertension: Systolic pressure is between 120–139 OR diastolic pressure is between 80–89.
High blood pressure (Stage 1): Systolic pressure is between 140–159 OR diastolic pressure is between 90–99.
High blood pressure (Stage 2): Systolic pressure is 160 or higher OR diastolic pressure is 100 or higher.

An individual’s blood pressure can change from minute to minute with changes in posture, exercise, stress or sleep. It should, however, normally be less than 120/80 mmHg for individuals aged 20 or over. All levels above 120/80 mmHg raise an individual’s risk of developing high blood pressure and the risk grows as blood pressure levels rise. Untreated high blood pressure increases the strain on the heart and arteries, eventually causing organ damage and increasing the risk of heart failure, heart attack and stroke.

Risk Factors

High blood pressure has many risk factors. Risk factors that cannot be controlled include:

Age: The risk of high blood pressure increases with age. Over half of all Americans aged 60 and older have high blood pressure.
Race or Ethnicity: In the U.S., high blood pressure is more common among African–Americans than Caucasians. African–Americans tend to develop high blood pressure earlier in life and have higher rates of premature death from high blood pressure–related complications such as coronary heart disease, stroke and kidney failure.
Family History: Individuals with family members who have high blood pressure, cardiovascular disease or diabetes are at higher risk.
Gender: Until 45 years of age, a higher percentage of men have high blood pressure than women. From ages 45 to 64, the percentages of men and women with high blood pressure are similar. Beginning at age 65, however, after the onset of menopause, a much higher percentage of women have high blood pressure than men.

According to the NHLBI, a number of controllable risk factors also increase an individual’s risk of high blood pressure. These include:

Eating too much sodium (salt): Approximately 77 percent of the sodium that Americans consume comes from processed and restaurant foods. Excess sodium can increase blood pressure and the risk of heart attack and stroke.
Drinking too much alcohol: Over time, heavy drinking can increase blood pressure dramatically and damage the heart. Heart failure, stroke and irregular heartbeat can result.
Not getting enough potassium in the diet: Potassium helps to balance the amount of sodium in the body. Individuals who do not consume or retain enough potassium may accumulate excess sodium in the blood.
Being overweight or obese: Being overweight or obese can cause high blood pressure. A body mass index between 25 and 30 is considered overweight; over 30 is considered obese. The more overweight that an individual is, the more blood he or she needs to supply oxygen and nutrients to the tissues. As the volume of blood circulated through the blood vessels increases, so does the pressure on the artery walls, resulting in increased blood pressure.
Physical inactivity: An inactive lifestyle increases the chance of high blood pressure, heart disease, blood vessel disease and stroke. Inactive individuals tend to have higher heart rates. When an individual’s heart rate is elevated, the heart must work harder with each contraction, resulting in greater pressure applied to the arteries. Additionally, physical inactivity can cause an individual to gain weight which can lead to high blood pressure.
Smoking: Smoking can damage the blood vessels and raise an individual’s risk of high blood pressure. It also can exacerbate health problems related to high blood pressure.

Additionally, certain chronic conditions including high cholesterol, diabetes, kidney disease and sleep apnea may also increase an individual’s risk of developing high blood pressure.

Diagnosis and Treatment

Many people who have high blood pressure do not know that they have it. According to the American Heart Association, of all people with high blood pressure, over 20 percent are unaware of their condition. High blood pressure is sometimes called the "silent killer" because it has no warning signs or symptoms. That is why individuals should make it a point to know their blood pressure numbers even when they are feeling fine.

Blood pressure is measured with an inflatable arm cuff and a pressure–measuring gauge. A physician will most likely take two or three blood pressure readings at several separate appointments before making a diagnosis of high blood pressure. This is because blood pressure normally varies throughout the day — sometimes specifically during visits to the doctor. Upon diagnosis by a healthcare professional, high blood pressure can usually be managed through lifestyle changes and, when necessary, medication.

Adopting a healthy lifestyle is critical for the prevention of high blood pressure and is an indispensable part of managing the condition. Individuals can take steps each day to keep blood pressure levels normal by modifying any of their controllable risk factors. Changing lifestyle habits can go a long way toward controlling high blood pressure. Specifically, individuals should:

Maintain a healthy weight
Be physically active
Follow a healthy eating plan
Reduce sodium in the diet
Drink alcohol only in moderation

Sometimes, however, lifestyle changes are not enough. A healthcare professional may determine that prescription medication is needed in addition to lifestyle changes. There are various medications that are commonly used to treat high blood pressure. Some remove extra fluid and salt from the body to lower blood pressure, while others slow down the heartbeat or relax and widen blood vessels. Some individuals will respond well to one medication but not to another; often, two or more medicines work better than one. It may take time to determine the right medication(s) and proper dosage(s) to effectively lower blood pressure with a minimum of side effects. It is important for individuals to take medications for high blood pressure exactly as prescribed for as long as instructed by their doctors.

The health consequences of high blood pressure are serious and cumulative. Have your blood pressure checked regularly. If your medical provider thinks that it is too high, you must work together as a team to reduce it.