Hypertension is explained in this video. Hypertension, also known as high blood pressure, is a very common and serious condition that can lead to and/or complicate many health problems. These include coronary heart disease, stroke, kidney failure and heart failure. About one in three adults in the U.S. have hypertension, according to the National Heart, Lung and Blood Institute. There are three general types of hypertension; Essential hypertension, occurs when the condition has no known cause, secondary hypertension, which caused by another condition or disease process, and isolated systolic hypertension, occur when systolic blood pressure number (the top number), common in older adults.