Blood pressure is the force of blood against artery walls. It is measured in millimeters of mercury (mmHg) and recorded as two numbers—systolic pressure (when the heart beats) over diastolic pressure (when the heart relaxes between beats). Both numbers are important. Blood pressure rises and falls during the day. But when it stays elevated over time, then it's called high blood pressure. High blood pressure is dangerous because it makes the heart work too hard, and the high force of the blood flow can harm arteries and organs such as the heart, kidneys, brain, and eyes.
High blood pressure often has no warning signs or symptoms. Once it occurs, it usually lasts a lifetime. If uncontrolled, it can lead to heart and kidney disease, stroke, and blindness. High blood pressure affects more than 65 million—or 1 in 3— American adults. About 28 percent of American adults ages 18 and older, or about 59 million people, have prehypertension, a condition that also increases the chance of heart disease and stroke.
High blood pressure is especially common among African Americans, who tend to develop it at an earlier age and more often than Whites. It is also common among older Americans—individuals with normal blood pressure at age 55 have a 90 percent lifetime risk for developing high blood pressure.
High blood pressure can be controlled if you take these steps:
- Maintain a healthy weight.
- Be moderately physically active on most days of the week.
- Follow a healthy eating plan, which includes foods lower in sodium.
- If you drink alcoholic beverages, do so in moderation.
- If you have high blood pressure and are prescribed medication,take it as directed.