there's word of caution for people being
treated for high blood pressure and I
need to give you a bit of a lesson first
in blood pressure there are two numbers
your systolic let's the top number like
you know you've told is 120 180 the top
number is the systolic pressure and
that's the pressure when your heart
beats the blood into your arteries the
bottom pressure is the diastolic
pressure and that's when the heart
relaxes the bottom number the diastolic
is important because that gives you the
background blood flow to your heart and
your brain now trial last year in people
at high risk of heart disease showed
that if you drive that top number the
systolic pressure down to about 120 or
lower you get significant benefits
particularly in stroke prevention but
probably also in preventing heart
attacks the word of caution comes from a
study in the last few weeks which looked
at the lower number diastolic because
the diastolic pressure becomes too low
what they found was that there's chronic
heart damage in some people so the
message for general practitioners and
consumers is if you're about to treat
somebody at higher risk of heart disease
for their blood pressure you've got to
look at both the top number and the
bottom number and if the bottom number
is already low you've just got to be
that little bit more careful in how low
you drive the blood pressure overall