The Early Show medical correspondent Dr. Emily Senay explains that high blood pressure, or hypertension, refers to the force of blood pressing against artery walls being too great, as that blood is pumped around the body by the heart.
It adds to the workload of the heart and arteries, and over time can damage the heart, arteries and other organs. It increases the risk of heart attack, stroke, kidney failure and heart failure.
A study in Wednesday's Journal of the American Medical Association looked at blood pressure in older adults, and finds that not only do most people over age 80 have high blood pressure, but most aren't getting effective treatment to control it.
Researchers measured blood pressure and heart health in more than 5,000 older people, tracking them for up to six years. Among the oldest age group, 80 and over, almost three quarters had high blood pressure. But only 38 percent of the men in that age group and 23 percent of the women had their blood pressure treated effectively.
Most people eventually develop high blood pressure as a result of old age, and the researchers say that controlling blood pressure is urgent for people in this age group.