According to the National Heart, Lung and Blood Institute, blood pressure is considered to be "high" over 140/90 (unless you have diabetes, which it then should be no higher than 130/80)...
Blood pressure at or above 140/90 is considered high blood pressure. Conversely, pressures below 100/60 (or in some cases, 90/60) are considered low blood pressure.
if your blood pressure is 120/80 or 140/90 mmHg its normal, if its 140/90 mmHg or higher you have high blood pressure and if its 180/110 mmHg or higher than that you have really high blood pressure.
Yes, blood pressure is a measure of the pressure exerted on your arterial walls as the heart pumps blood throughout the body (systolic) over the pressure when your heart is relaxed (diastolic).