Based on updated criteria, more American adults have high blood pressure (hypertension), according to a report published in April 2020 from the U.S. Centers for Disease Control and Prevention's (CDC) National Center for Health Statistics (NCHS). Many individuals with hypertension aren't aware they have this condition.
Blood pressure is the force that blood exerts on the walls of the arteries as it is pumped by the heart. Blood pressure readings measure two pressures, and the resulting numbers are written one over the other (e.g., 120/80). The top number (systolic blood pressure) is the force in blood vessels during a heartbeat. The bottom number (diastolic blood pressure) refers to the force when the heart relaxes between beats. A single elevated blood pressure reading is not diagnostic of hypertension. Usually, multiple readings are taken on different days. If the readings are consistently above the threshold, then a diagnosis of high blood pressure is made.
In 2017, the American College of Cardiology (ACC) in partnership with the American Heart Association (AHA) released new guidelines that lowered the previous threshold for diagnosing high blood pressure from 140/90 mmHg to 130/80 mmHg. Using this new threshold, roughly 45% of Americans age 18 and older are estimated to have high blood pressure, compared to 31% using the older definition, according to the NCHS report.
Not all health professional organizations agree with the new blood pressure thresholds defined by the ACC/AHA guidelines, however, and the medical community has not yet reached consensus on the issue. Some experts say that the under-130 goal is too aggressive, and treatment could be more harmful than beneficial for some patients.
According to the new report, high blood pressure is a key risk factor for cardiovascular disease and lowering blood pressure has been shown to decrease the number of newly diagnosed cases of stroke, heart attack, and heart failure as well as other conditions such as kidney failure. Lowering the threshold for diagnosis of high blood pressure is expected to result in earlier treatment of the condition, notes the report. This will hopefully decrease some individuals' risk of developing cardiovascular disease.
To determine how many American adults have high blood pressure, NCHS researchers analyzed data from the National Health and Nutrition Examination Surveys (NHANES) administered during the years 1999–2018. These surveys gauge health and nutritional status by combining interviews and physical examinations of participants.
The researchers used data from 10 two-year cycles (1999–2000 through 2017–2018) to spot trends in the estimated percentage of Americans with high blood pressure by age, sex, level of education, and racial/ethnic background. They used the new blood pressure diagnostic threshold to evaluate the data.
The researchers found that during 2017-2018:
- High blood pressure was more common in men that women. About 51% of men had the condition, compared to 40% of women.
- High blood pressure was more common in non-Hispanic blacks than non-Hispanic whites or Hispanics. Slightly more than 57% of non-Hispanic blacks had high blood pressure, compared to 44% of non-Hispanic whites and 44% of Hispanics.
- The rate of high blood pressure was lowest among college graduates, compared to those with less education. This trend was similar among both men and women.
The researchers also applied the 2017 definition of high blood pressure to the data to evaluate trends over time. They found that the overall proportion of NHANES participants with high blood pressure decreased from 47% in 1999–2000 to 42% in 2013–2014, but then increased to 45% in 2017–2018. The proportion of men with high blood pressure showed a similar pattern, decreasing from 52% in 1999–2000 to 45% in 2013–2014, and then rising to 51% in 2017–2018. However, the proportion of women with high blood pressure did not change significantly over time. During 1999-2000, that figure was 42% versus 40% in 2017–2018.
Monitoring blood pressure regularly is important because high blood pressure usually has no symptoms, even though it increases risk of serious health problems. Even life-threatening high blood pressure causes a few non-specific symptoms, such as headaches, dizziness, or frequent nosebleeds.
For this reason, high blood pressure is known as the "silent killer," quietly increasing the risk of developing heart disease and suffering stroke, heart attack, and heart failure. High blood pressure also increases risk of damage to the eyes, kidneys, and brain. The greater the blood pressure for extended periods, the greater the potential for damage. Because of this, it is important to get your blood pressure checked regularly.
If you have high blood pressure, your healthcare practitioner may recommend that you adopt lifestyle changes that include a healthy, low-salt diet, regular exercise, avoiding alcohol, quitting smoking, managing stress, and getting enough sleep. If lifestyle changes are not enough, healthcare practitioners may prescribe blood pressure medications that prevent narrowing of blood vessels, allow vessels to relax, remove extra water and salt from the body, or help the heart beat more slowly and with less force.
For more details, see the articles on screening recommendations for Young Adults, Adults and Adults over age 50.