The Journal
What your blood tests actually mean
Most testing sites hand you numbers. We explain them: what each marker measures, why it matters, and what to do next. Plain English, grounded in the evidence.
Guides · Featured
The PSA test: what it can and cannot tell you
PSA is the main blood test we have for prostate cancer, and it is genuinely useful. It is also imprecise in both directions. Knowing that before you test is the difference between a number that helps and a number that frightens you.
8 min read · 29 Jul 2026
Heart & circulation
apoB: the cholesterol number that actually matters
A standard cholesterol test weighs the cargo. apoB counts the delivery trucks, and the number of trucks tells you more about what ends up in your artery walls than the cargo does.
6 min read · 7 Jul 2026
Metabolic health
HbA1c: your blood sugar, averaged over three months
A finger-prick glucose is a single snapshot, high after lunch, low before breakfast. For most people HbA1c is the running average of your blood sugar over about three months, which is why it's the number used to judge diabetes risk.
5 min read · 6 Jul 2026