Precision health gets used as a marketing word. Here it means something specific: starting from the individual system rather than the population average, and designing from what's actually there rather than what usually works.
The gap between ‘normal’ and ‘optimal’ is where most of the useful work happens. A result can sit inside the reference range and still be wrong for you. Reading that difference is the foundation everything else is built on.
Average advice, individual bodies
Population studies tell you what happens on average. They cannot tell you what happens to you. When standard advice fails, the usual conclusion is that the person didn’t try hard enough — when the real issue is that the advice was never built for their particular system in the first place.
Reading a system, not treating a symptom
A symptom is the visible end of a chain. Treating it without reading the chain behind it is guesswork. The practice starts upstream: what is the system actually doing, and why, before deciding what to change.
Reference ranges and functional ranges
The standard reference range describes the spread of a population, including a lot of people who feel unwell. The functional range asks a different question: where does this marker sit when a body is actually working well? The space between the two is often where someone has been living for years.