The medical term for high blood pressure is hypertension. High blood pressure is dangerous because it makes the heart work too hard and contributes to atherosclerosis (hardening of the arteries).
It increases the risk of heart disease and stroke, which are the first- and third-leading causes of death among Americans. It also increases the risk for dementia. High blood pressure also can result in other conditions, such as congestive heart failure, kidney disease, and blindness.
A blood pressure level of 140/90 mmHg or higher is considered high. About two-thirds of people over age 65 have high blood pressure. If your blood pressure is between 120/80 mmHg and 139/89 mmHg, then you have a condition known as prehypertension. This means that you don’t have high blood pressure now but are likely to develop it or at risk of developing it in the future. You should take steps to prevent the onset of high blood pressure by adopting a healthy lifestyle.
Those who do not have high blood pressure at age 55 have a 90 percent chance of developing it during their lifetimes. So high blood pressure is a condition that most people have at some point in their lives.
Both numbers in a blood pressure test are important, but for people who are 50 or older, systolic pressure gives the most accurate diagnosis of high blood pressure. Systolic pressure is the top number in a blood pressure reading. It is high if it is 140 mmHg or above.