Important news regarding the blood tests we all undergo
Here is what happens when we have our blood tested: Once a blood sample has been processed through the appropriate testing mechanism, the result is typically compared to an average derived from a general population spanning nearly all ages. In other words, our results are considered "normal" if they fall within a usually quite broad range defined by that population—or "abnormal" if they fall outside it.
However, for several reasons, this expansive definition of "normal" can be problematic. For instance, we have repeatedly pointed out in these pages that reproductive hormone levels should be interpreted in an age-dependent context—something that still happens only rarely.
A recent and important study has introduced an additional and very logical consideration. Using the complete blood count (CBC)—perhaps the most commonly ordered blood test in medicine—as an example, the study demonstrated that individual results tend to be remarkably stable over time. Significant deviations from a person’s typical values may, in fact, signal the onset of disease.¹
The study found that personal "setpoints" in healthy adults were linked to meaningful clinical risks. For example, the absolute risk of developing certain diseases—such as myocardial infarction, stroke, diabetes, kidney disease, and osteoporosis—varied by more than 2%. Even more striking, the absolute risk for 10-year mortality varied by over 5%. Here is very obviously yet another job waiting for A.I.!
Reference
1. Fot et al., Nature 2025;637:430-438