There were other applications proposed in the early days of the. Internet, including packet based voice communication (the. precursor of Internet telephony), various models of file and disk. sharing, and early âwormâ programs that showed the concept of. agents (and, of course, viruses). A key concept of the Internet is.
View All. For a long time, normal blood pressure was defined as 120/80 mm Hg (systolic/diastolic). Recently, however, the American Heart Association revised its guidelines about what an optimal blood pressure range is, and when blood pressure is considered too high or too low. While 120/80 used to be considered normal, the new guidelines define three levels of abnormal blood pressure values. 120-139 / 80-89 is now considered to be âprehypertensionâ (or âalmost high blood pressure), and doctors are watching blood pressures in this range more carefully than in the past.
When your heart beats, it contracts and pushes blood through the arteries to the rest of the body. This force creates pressure on the arteries. This is called systolic blood pressure. A normal systolic blood pressure is below 120. A systolic blood pressure of 120 to 139 means you have prehypertension, or borderline high blood pressure.