November 1, 2026 · 5 min
The two numbers on a blood pressure reading
What the top number and the bottom number each stand for.
The letter
A letter every Sunday
One idea about how the heart works, in words you can read over coffee, and the dates of my next talks. Free, and short.
More posts
Why your pulse changes on a walk
What the beat is doing when you climb a slope, and what it is doing at rest.
Why I write this letter
From a hospital ward to a whiteboard in a community hall.