Blood pressure is the force in the arteries when the heart beats (systolic pressure) and when the heart is at rest (diastolic pressure). It’s measured in millimeters of mercury (mm Hg). High blood pressure (or hypertension) is defined in an adult as a blood pressure greater than or equal to 140 mm Hg systolic pressure or greater than or equal to 90 mm Hg diastolic pressure.
High blood pressure directly increases the risk of coronary heart disease (which leads to heart attack) and stroke, especially when it’s present with other risk factors.
High blood pressure can occur in children or adults, but it’s more common among people over age 35. It’s particularly prevalent in African Americans, middle-aged and elderly people, obese people, heavy drinkers and women taking birth control pills. It may run in families, but many people with a strong family history of high blood pressure never have it. People with diabetes mellitus, gout or kidney disease are more likely to have high blood pressure, too.
American Heart Association recommended blood pressure levels:
|Blood Pressure Category||Systolic (MM HG)||Diastolic (MM HG)|
|Normal||Below 120||and less than 80|
|Stage 1||140–159||or 90–99|
|Stage 2||160 or higher||or 100 or higher|
Common Misconceptions about High Blood Pressure
1. Nervousness, sweating and difficulty sleeping are common symptoms of high blood pressure.
High blood pressure has NO symptoms. That’s why it’s often called the “silent killer.” The only way to know if you have it is to have your blood pressure checked. Some people who look and feel fit and healthy may find that they have high blood pressure. Likewise, some people who have other risk factors for heart disease and/or stroke (such as being overweight or smoking) may not have high blood pressure. According to recent estimates, about one in three U.S. adults has high blood pressure, and nearly one-third of them don’t know it. That puts them at risk for stroke, heart attack, heart failure, kidney disease and even blindness in some cases.
2. Every time I go to the doctor, my blood pressure is high, but that’s just because I’m nervous. I’m sure my blood pressure is OK at home.
Some people may experience what’s called “white-coat hypertension” when they’re at the doctor’s office. This means their blood pressure is elevated temporarily due to nervousness. Many things can affect your blood pressure, including physical exertion, emotional fluctuations and stress. Monitoring at home may be one way to measure your true blood pressure and give your doctor a log of blood pressure measurements over time. Even though there are factors that can affect your blood pressure, you should never ignore several readings that indicate you may have high blood pressure.
3. If you have high cholesterol, you automatically have high blood pressure.
High blood cholesterol doesn’t automatically lead to high blood pressure, but many of the same lifestyle habits that may increase blood cholesterol levels also may cause elevated blood pressure. Examples include a diet high in saturated fat, lack of physical activity and drinking too much alcohol. Uncontrolled high blood pressure can lead to stroke, heart attack, hardening of the arteries, congestive heart failure and/or kidney disease. In some cases, it can cause blindness. High blood pressure can only be detected by having it checked.
4. These days everyone has high blood pressure. It’s just a fact of life, and I don’t need to worry about it.
These are stressful times, and stress may add to your risk factors for high blood pressure. That’s why it’s so important to have your blood pressure checked. About 69 percent of people who have a first attack, 77 percent who have a first stroke, and 74 percent who have congestive heart failure have BP higher than 140/90 mm Hg. Also, high blood pressure is the No. 1 modifiable risk factor for stroke. On average every 40 seconds, someone in America has a stroke. That means about 780,000 Americans will have a stroke this year; about 150,000 of them will die. Stroke is our nation’s No. 3 killer and a leading cause of severe, long-term disability.
5. I took my high blood pressure medication for a while, but I’m feeling much better now. I figure it’s OK to cut it back or even quit.
High blood pressure is a lifelong disease. It can be controlled but not cured. If your doctor has prescribed medication for you, take it exactly as prescribed for as long as the doctor tells you to take it. Decreasing dosage or not taking the medication is dangerous. It’s also important to make the right lifestyle changes by eating a diet rich in fruits, vegetables and whole-grain high-fiber products; choosing fat-free and low-fat dairy products, legumes, poultry and lean meats; and eating fish, preferably omega-3 containing fish (e.g. salmon, trout, herring). Such a diet is low in saturated fat, trans fat, cholesterol and sodium (salt), and high in potassium. Dietary potassium from fruits, vegetables and fat-free or low-fat dairy may help lower your blood pressure. You should also attain and maintain a healthy weight, get plenty of physical activity (at least 30 minutes of moderate intensity on most or all days of the week) and stay away from tobacco products. This will help control your blood pressure and thus reduce your risk for stroke, heart attack, heart failure and kidney disease.
6. High blood pressure is a man’s problem. I’m a woman so I don’t have to worry.
High blood pressure can be anyone’s problem. In fact, women need to be aware of certain things that may put them at a greater risk for high blood pressure than men. If you’re on the Pill, pregnant, overweight, postmenopausal, African American or have a family history of high blood pressure, you may be more likely to have high blood pressure. It’s important to get the facts so you can reduce your risk for stroke, heart disease or kidney disease by controlling as many high blood pressure risk factors as you can.
7. I can take any kind of over-the-counter medications when I have a cold or the flu.
That’s not true. People with high blood pressure should know that taking certain cold, cough and flu medications could be dangerous. Decongestants have been reported to increase blood pressure and may interfere with blood pressure medications. Many over-the-counter drugs can have a dangerous effect on certain heart conditions and increase your risk for heart disease, heart attack and stroke. If you’re one of the 73 million Americans who have high blood pressure, make sure to choose cold and flu medications that don’t contain decongestants.
8. You don’t need to have your high blood pressure checked until you reach middle age.
It’s a good idea to start having your blood pressure checked at an early age — even children as young as 6 can have high blood pressure. When kids reach the teen years, they should certainly have their pressure checked. According to research, teenagers with the highest blood pressure and extra pounds have thicker arteries by age 30. Preventing fatty buildups in artery walls may depend on keeping boys and girls from becoming overweight as adolescents or helping them lose excess weight if they’re already obese. Age, body size and the degree of sexual maturation determine blood pressure levels in adolescence. Heavier and more sexually mature teenagers tend to have higher blood pressure.
How does high blood pressure develop?
Your heart pumps blood through the body’s arteries. The large arteries that leave your heart taper into smaller arteries called arterioles. The arterioles then taper into smaller vessels called capillaries, which supply oxygen and nutrients to all the organs of your body. The blood then returns to your heart through the veins.
Certain nerve impulses cause your arteries to dilate (become larger) or contract (become smaller). If these vessels are wide open, blood can flow through easily. If they’re narrow, it’s harder for the blood to flow through them, and the pressure inside them increases. Then high blood pressure may occur. When this happens, your heart becomes strained and blood vessels may become damaged. Changes in the vessels that supply blood to your kidneys and brain may cause these organs to be affected.
Your heart, brain and kidneys can handle increased pressure for a long time. That’s why you can live for years without any symptoms or ill effects. But that doesn’t mean it’s not hurting you. High blood pressure is a major risk factor for stroke, heart attack, heart failure and kidney failure.
What does high blood pressure do to your body?
High blood pressure adds to the workload of your heart and arteries. Your heart must pump harder, and the arteries carry blood that’s moving under greater pressure. If high blood pressure continues for a long time, your heart and arteries may not work as well as they should. Other body organs may also be affected. There is increased risk of stroke, congestive heart failure, kidney failure and heart attack. The risk of heart attack or stroke increases several times when high blood pressure exists with obesity, smoking, high blood cholesterol or diabetes.
What about low blood pressure?
Within certain limits, the lower your blood pressure reading is, the better. In most people, blood pressure isn’t too low until it produces symptoms, such as lightheadedness or fainting. In certain disease states, it’s possible for blood pressure to be too low. Examples include:
- Certain nerve or endocrine disorders
- Prolonged bed rest
- Decreases in blood volume due to severe bleeding (hemorrhage) or dehydration
Blood pressure less than 120/80 mm Hg is generally considered ideal. Levels higher than this increase your risk for cardiovascular disease. If you have unusually low blood pressure, have it evaluated.