Hearts at risk:

understanding basics of blood pressure
Measuring your blood pressure is quick and painless. Photo credit:CDC/AmandaMills

Measuring your blood pressure is quick and painless. Photo credit:CDC/AmandaMills

Healthy hearts face risks from many different factors: high cholesterol, obesity, diabetes, tobacco use, an unhealthy diet, physical inactivity and secondhand smoke, among others. But another common — and often misunderstood — risk factor is high blood pressure.

One in three Americans suffers from high blood pressure, according to the American Heart Association (AHA). With February designated as American Heart Month, now is a great time to understand more about this condition.

Blood pressure is typically recorded as two numbers, written as a ratio: 118/75 mm Hg. The top number, systolic, measures pressure in the arteries when a heart beats and the heart muscle contracts. The bottom number, diastolic, measures pressure in the arteries between heartbeats (when the heart muscle rests between beats and refills with blood).

The AHA lists five stages of blood pressure:

  • Normal: Systolic less than 120 and diastolic less than 80
  • Prehypertension: Systolic between 120–139 or diastolic between 80–89
  • High Blood Pressure Stage 1: Systolic between 140–159 or diastolic between 90–99
  • High Blood Pressure Stage 2: Systolic 160 and higher or diastolic 100 or higher
  • Hypertensive Crisis (emergency care needed): Systolic 180 and higher or diastolic 110 or higher

How is high blood pressure diagnosed?

Health care providers want an accurate picture of blood pressure to chart what happens over time. Starting at age 20, AHA recommends a blood pressure screening at least once every two years.

If a patient's blood pressure reading comes in higher than normal, a doctor may take several readings over time and/or have the patient monitor blood pressure levels at home before diagnosing high blood pressure.

A single high reading does not necessarily translate to high blood pressure. However, if readings stay at 140/90 mm Hg or above (systolic 140 or above OR diastolic 90 or above) over time, a doctor will likely begin a treatment program. Such a program almost always includes lifestyle changes and often prescription medication.

If, while monitoring blood pressure, a patient notes a systolic reading of 180 mm Hg or higher OR a diastolic reading of 110 mm HG or higher, the patient should wait a few minutes and try again. If the reading remains at or above that level, a patient should seek immediate emergency medical treatment for a hypertensive crisis.

Which number is more important?

Of course both numbers are important, but typically more attention is given to the top number (the systolic blood pressure) as a major risk factor for cardiovascular disease for people over 50. In most cases, systolic blood pressure rises steadily with age because of increasing stiffness of large arteries, long-term build-up of plaque, and increased incidence of cardiac and vascular disease.

Preventing heart disease

Heart disease, including stroke, is the leading cause of death for men and women in this country. You are at higher risk of heart disease if you are:

  • A woman age 55 or older
  • A man age 45 or older
  • Or a person with a family history of early heart disease

To keep your heart healthy:

  • Watch your weight.
  • Quit smoking and stay away from secondhand smoke.
  • Control your cholesterol and blood pressure.
  • If you drink alcohol, drink only in moderation.
  • Get active and eat healthy.
  • Consult your doctor about taking aspirin every day if you are a man over the age of 45 or a woman over 55.
  • Manage stress.

To learn more, visit www.heart.org

Sources: American Heart Association; National Health Information Center

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