Where There Is No Doctor 2011 411
1. 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 120 mm.
2. 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 80 mm.
When you record a person’s blood pressure, always write both the top and
bottom pressure readings. We say that an adult’s normal blood pressure (BP) is
“120 over 80,” and write it like this:
120 is the top (systolic) reading.
80 is the bottom (diastolic) reading.
For health workers, it may be better to speak of the “top” and “bottom” numbers
(TN and BN), rather than use big, strange words like systolic and diastolic.
If a person’s blood pressure is 160/110, he has
seriously high blood pressure and should lose weight (if
he is very overweight) or get treatment. A bottom number
of over 100 or a top number over 160 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 blood or at risk of shock (see p. 77).
For more information about blood pressure measurement, see Helping Health
Workers Learn, Chapter 19.