Blood pressure basics

Everybody has and needs blood pressure. Without it, blood can’t circulate through your body. And without circulating blood, your vital organs can’t get food they need to work. That’s why it’s important to know about the basics of blood pressure and how to keep it in the normal range.

When your heart beats, it pumps blood into your arteries, and creates pressure in them. This pressure (blood pressure) causes your blood to flow to all parts of your body. If you’re healthy, your arteries are elastic. They stretch when your heart pumps blood through them. How much they stretch depends on how much force the blood exerts.

Your heart beats about 60 to 80 times a minute under normal conditions. Your blood pressure rises on contractions and falls when your heart relaxes between beats. Your blood pressure can change rapidly, with changes in stress levels, posture, physical activity or during sleep.

Here are the most common questions people ask about blood pressure:

What is blood pressure?

Two numbers are recorded when measuring your blood pressure, such as 120/80 mm Hg (millimeters of mercury). The top or larger number (systolic pressure) measures the pressure in your arteries when your heart beats. The bottom or smaller number (diastolic pressure) measures the pressure while your heart rests between beats.

Normal pressure is below 120/80 mm Hg. Blood pressure of 120-139/80-89 is considered “prehypertension.” If you’re an adult and your blood pressure is 140/90 mm Hg or higher, you have high blood pressure. If you have diabetes or kidney disease, your doctor will want your blood pressure to be lower than 130/80 mm Hg. If your blood pressure goes above the threshold and stays there, you have high blood pressure. Your doctor may take several readings over time before making a judgment about high blood pressure.

What causes high blood pressure?

High blood pressure, also called hypertension, isn’t nervous tension. People who have high blood pressure don’t have to be tense or nervous. High blood pressure usually has no symptoms. That is why it is called the “silent killer.”

About 90 to 95 percent of people with high blood pressure have no known cause. But some factors increase your chances of developing this disease. These are called risk factors.

What are the risk factors you can control?

• Obesity. People with a body mass index (BMI) of 30 or higher are more likely to develop high blood pressure.

• Eating too much salt. This increases blood pressure in some people.

• Alcohol. Heavy and regular use of alcohol can increase blood pressure dramatically.

• Lack of physical activity. An inactive lifestyle makes it easier to become overweight and increases the chances of high blood pressure.

• Stress. This is often mentioned as a risk factor. However, stress levels are hard to measure, and responses to stress vary from person to person.

What are the risk factors you can’t control?

• Race. Certain races (e.g. African Americans) develop high blood pressure more than others. In the Philippines, it is estimated that there are about 13 million hypertensive Filipino adults and this number has been steadily rising since 2008.

• Heredity. A tendency to have high blood pressure runs in families. If your parents or other close relatives have it, you’re likely to develop it.

• Age. In general, the older you get, the greater your chance of developing high blood pressure. A higher percentage of men have HBP until age 45. From 45-54, the percentages of men and women are similar. After that, a much higher percentage of women have high blood pressure than do men.

Can you tell when your blood pressure is high?

No, definitely not. High blood pressure usually has no symptoms. In fact, many people have it for years without knowing it. That’s why it is so dangerous. The only way to find out if you have this disease is to have your blood pressure measured. Your doctor or another health professional can check it for you.

Can high blood pressure damage your body?

Yes. It can hurt your body in many ways. Mainly, it adds to the workload of your heart and arteries. Because your heart must work harder than normal for a long time, it tends to get bigger. A slightly enlarged heart may still work well, but if it’s enlarged very much, it may have a hard time meeting your body’s demands.

As you get older, your arteries will harden and become less elastic. This occurs in all people regardless of blood pressure. But having high blood pressure tends to speed up this process.

High blood pressure increases your risk of stroke. It can also damage your kidneys and eyes. Compared with people with controlled blood pressure, people with uncontrolled hypertension are also more likely to develop coronary heart disease and congestive heart failure.

If you have high blood pressure, follow your doctor’s advice. Most high blood pressure can’t be cured, but it usually can be controlled. And its effects can be prevented or reduced – if it’s treated and controlled early.

What can be done about high blood pressure?

Most treatments for high blood pressure rely on some combination of losing weight, diet, regular physical activity and medication. Here’s a brief discussion of each option:

• Diet. Your physician and other qualified health professionals (nurses, dietitians, etc.) can help you start or follow a diet that will help you reduce your blood pressure and control your weight. It will include eating more fruits and vegetables, whole grain cereals, rice and bread, and less fried food and fatty meals.

• Weight reduction. Many people with high blood pressure are also overweight. If that’s true of you, your doctor can prescribe a diet for you. Often when people lose weight, their blood pressure drops too. Being overweight is a risk factor for heart disease. By losing weight, you may help reduce your blood pressure and help you stay healthy in other ways, as well.

If you’re given a diet, follow it closely, including advice about reducing how much alcohol you drink. Alcoholic drinks are low in nutrients but high in calories, so if you’re trying to lose weight, avoid them.

Sometimes, eating less sodium can help lower blood pressure. If this might help you, your doctor will recommend a low-salt diet. This means you have to avoid salty foods, cut down on how much salt you use in cooking and at the table, and start reading package labels regularly to learn about the sodium content of prepared foods. Most Filipinos eat much more salt than they need. By experimenting with herbs and spices as seasoning, you can still enjoy tasty meals.

• Physical activity. Don’t be afraid to be active. Physical activity should be part of your daily program. It helps to reduce blood pressure and it can even help you lose weight or stay at your best weight. Your doctor can suggest the best kind of exercise program for you. Whatever physical activity you enjoy and do regularly will probably be just fine. A minimum of 30 minutes of physical activity on most days of the week is recommended.

• Medications. Some people need medication to help them reduce high blood pressure. Many drugs are available for this. Some remove excess fluid and salt. Others open up and expand narrowed blood vessels, while others prevent blood vessels from constricting and narrowing. Medicines lower blood pressure in many cases but every person reacts differently to medications. Your doctor will be in the best position to prescribe what is best for your specific needs. You may need a trial period before your doctor finds the best medicine or combination of medicines for you.

Treating blood pressure is manageable in many instances. But it may be complicated in some cases and require lots of time, patience, and care by both you and your doctor. Some people can reduce their drug dosages after achieving normal blood pressure and maintaining it for a year or more. Enduring this inconvenience is still much better than suffering a stroke or heart attack. Most people who are successfully treated live a long and healthy life. –Tyrone M. Reyes, M.D. (The Philippine Star)

* * *

Sources: American Heart Association, at americanheart.org and Hypertension: Controlling the “silent killer,” at www. health.harvard.edu/hypertension.