Blood pressure is the force of blood against the walls of arteries. Blood pressure rises and falls during the day. When blood pressure stays elevated over time, it is called high blood pressure.
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. High blood pressure also can result in other conditions, such as congestive heart failure, kidney disease, and blindness.
Pre-hypertension is a term used to describe blood pressure that is higher than normal but not high enough to be considered high blood pressure. Pre-hypertension is when the systolic blood pressure is between 120 and 139 or the diastolic blood pressure is between 80 and 89 on at least three readings. If a person has pre-hypertension, he/she will likely develop high blood pressure. Like high blood pressure, pre hypertension generally does not show symptoms.