As the needle of the gauge (or the level of mercury) slowly drops, take two readings:
●Take the first reading the moment you begin to hear the soft thumping of the pulse. This happens when the pressure in the cuff drops to the highest pressure in the artery (systolic or top pressure). This top pressure is reached each time the heart contracts and forces the blood through the arteries. In a normal person, this top pressure reading is usually around 110 to 120mm.
●Continue to slowly release the pressure while listening carefully. Take the second reading when the sound of the pulse begins to fade or disappear. This happens when the pressure in the cuff drops to the lowest pressure in the artery (diastolic or bottom pressure). This bottom pressure occurs when the heart relaxes between pulses. It is normally around 60 to 80mm.
When you record a person's blood pressure, always write both the top and bottom pressure readings. We say that an adults normal blood pressure (BP) is '120 over 80', and write it like this:
BP 120/80. 120 is the top (systolic) reading
80 is the bottom (diastolic) reading
It is usually the bottom number that tells us more about a person's health. For example, if a person's blood pressure is 140/85, there is not much need for concern. But if it is 135/110, he has seriously high blood pressure and should lose weight(if fat) or get treatment. A bottom number of over 100 usually means the blood pressure is high enough to require attention (diet and perhaps medicine ).
Normal blood pressure for an adult is usually around 120/80, but anything from 100/60 to 140/90 can be considered normal.
If a person regularly has low blood pressure, there is no need to worry. In fact, blood pressure on the low side of normal, 90/60 to 110/70., means a person is likely to live long and is less likely to suffer from heart trouble or stroke.
A sudden drop in blood pressure is a danger sign, especially if it falls below 60/40. Health workers should watch for any sudden drop in the blood pressure of persons who are losing or at risk of shock.
