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.
The first number is the systolic pressure, when your heart pushes blood around your body. The second is the diastolic pressure, when your heart relaxes. Blood pressure usually ranges between 90 to 250 for the top or maximum number (systolic) and 60 to 140 for the bottom or minimum number (diastolic). A healthy blood pressure is 120/80 or less, but the lower you can get it, the better. To maintain a healthy level and reduce your risk of stroke and heart disease, check out our lifestyle tips. 140/90mmHg is the level used to diagnose high blood pressure for everyone, whatever your age.