In article ,
he BOTTOM number, the one we all concern
ourselves

Er .. no.

Both numbers are important, but most people are more concerned about
the top one. (Perhaps wrongly so, but in any event, the important
number is the one that is high for its range. 160/70 ought to worry
you, and so should 130/110.)

Both numbers are important, so is the difference between the numbers.
Worst outcmes have been observed with wide pulse pressures. The upper
number is the systolic blood pressure, and the lower number is the
diasytolic blood pressure. SBP and DBP. DBP reflects the pressure at
rest, and SBP reflects the increase in pressure when your heart
squeezes/pumps blood. High DBP is bad for 'end organ damage' (kidneys,
eyes, liver, etc). High SBP is bad for 'popping things': stroke, heart
attack, ulcers, etc.
A wide difference between the numbers (low resting pressure, but high
pressure to pump/move blood) normally means theres a 'blockage' somewhere
(often in the heart, eg. aortic stenosis; CAD leading to a blockage to the
brain, etc).
A lot of 'older' citizens will develop only high SBP. There's some
debate about the risk factors for having a normal DBP with a high SBP, but
on the whole we try to treat everyone. The problem is that most meds drop
both, so you don't have a lot of room to play with if someone is 160/75