Quick answer
What do my blood test results mean?
A blood-test reference range describes values seen in most people in a comparison population; it is not a sharp line between healthy and ill. Results must be interpreted with symptoms, history, medicines and previous tests. A mildly flagged result can be harmless, while a result inside range may still need context.
Reference ranges are context, not diagnosis
Laboratories flag results outside their range, but age, sex, pregnancy, ethnicity, medicines and the reason for testing can alter interpretation.
Look at patterns
Clinicians compare related markers and earlier results. A repeat test may show that a borderline result was temporary or confirm a trend that needs investigation.
Ask what happens next
Useful questions are: Was anything important abnormal? Does it explain my symptoms? Do I need a repeat test, medicine change or appointment? When and how will follow-up happen?
Common questions about the understanding blood test results
- Why is my result marked abnormal when I feel well?
- Reference ranges usually contain about 95% of a comparison population, so some healthy people fall outside them. Context determines significance.
- Can dehydration change blood results?
- Yes. Hydration, recent food, exercise, infection, medicines and sample handling can influence some results.
- Who should explain my results?
- The GP or clinical team that requested the test should explain what the results mean for you and whether anything happens next.