A blood pressure of 140/90 or higher is considered high blood pressure. Both numbers are important. If one or both numbers are usually high, you have high blood pressure. If you want to measure your blood pressure at home, you will need to get a home blood pressure monitor. But it is important to choose accurate and the right Blood pressure monitor for you.
http://www.chemistdirect.co.uk/omron-m2-basic-blood-pressure-monitor_1_157913.html