The evidence behind every marker

What makes a test evidence-grade

• Accredited laboratories

  Every sample is analysed in UKAS-accredited UK laboratories to ISO 15189 — the same accreditation standard NHS pathology laboratories are held to. Accreditation means an independent body has verified the lab's methods, equipment and competence.

• Validated methods and quality control

  The markers we report are measured with validated clinical assays that run internal quality controls and take part in external quality-assurance schemes — the same checks that keep NHS pathology reliable.

• Reference ranges with a source

  Each marker is read against a reference range, and where an optimal range differs from the standard clinical range we say so and say why. The clinical guidance those ranges draw on is listed below, panel by panel.

What a blood test can — and can't — tell you

We would rather be the test that tells you the truth about its own limits. Here is the honest version.

• A blood test is a snapshot, not a diagnosis

  Your results describe one moment in time. A marker outside a reference range flags something worth understanding — it is not, on its own, a diagnosis of any condition. Diagnosis is a clinical judgement your GP makes with your full history and examination.

• Out of range does not mean unwell

  Reference ranges are population statistics: by design, some healthy people sit just outside them, and some people with a problem sit inside. We flag what is worth a closer look and, where a value warrants it, we tell you to speak to your GP.

• Some things blood cannot see

  Structural problems, most cancers, mental-health conditions and much else do not show up in the markers we measure. A normal Helvy result is reassuring for the markers tested — it is not an all-clear for your whole body.

• Timing and preparation change the numbers

  Fasting, time of day, recent exercise, illness and some medications all move biomarkers. We give you the preparation guidance that makes your result comparable, and we say so plainly when a marker is timing-sensitive.

If a result warrants medical attention we flag it clearly and tell you to speak to your GP. Helvy provides wellness guidance to help you understand your own data — it is not a diagnosis and not a substitute for professional medical advice.