An abnormal blood test result is a signal to interpret, not a diagnosis on its own. I look at the size and pattern of the change, the reason for testing, medicines, symptoms and earlier results before agreeing the safest next step.
Reference ranges are useful, but they do not replace a clinical assessment. A slightly out-of-range result may be temporary or unimportant in context, while a result within range may still need discussion when symptoms or trends suggest a problem.
At Victoria Medical, results are reviewed with the clinical question in mind. The response may be reassurance, a repeat test, a focused GP review, additional testing, imaging or a specialist referral. The route is tailored rather than automatic.
Written & reviewed by
Dr George XynopoulosMD, MRCP — Consultant Physician & Cardiologist
View full profileWhy a Result May Be Outside the Reference Range
Laboratory reference intervals describe a range found in many healthy people. They do not account for every individual factor, including recent illness, hydration, exercise, meals, medicines, supplements and the timing of the sample [1].
I also consider whether the result is isolated or part of a pattern. A group of related results, or a change from your own previous baseline, can be more informative than one value alone.
| Possible next step | Why it may be considered |
|---|---|
| Repeat the test | To check whether a temporary or pre-analytical factor affected the first sample. |
| Review symptoms and medicines | To interpret a result alongside the clinical context. |
| Order focused tests or imaging | When the pattern raises a specific question that needs clarification. |
| Arrange GP or specialist review | When the result, symptoms or trend need a management plan. |
A Safe Route for Follow-Up
Do not change prescribed medication, begin high-dose supplements or assume a diagnosis based on a result alone unless a clinician has advised you. Bring the complete report, previous relevant results and a list of medicines to a follow-up appointment.
If you are acutely unwell, have chest pain, severe breathlessness, fainting, confusion, rapidly worsening weakness, heavy bleeding, jaundice with severe illness, or another emergency symptom, use urgent services. Call 999 for a life-threatening emergency; a routine blood-test review must not delay emergency care.
When a Repeat Test May Be Useful
Repeat testing can help confirm whether a change persists, establish a trend or monitor the effect of a treatment. The interval depends on the marker, how abnormal it is, symptoms and the clinical question; a generic repeat interval is not safe for every result.
For example, unexpected liver markers are assessed using the full panel and clinical context, while kidney function follow-up may involve repeat eGFR and urine assessment [2][3].
What to Expect at Your Appointment
Clarify the clinical question
I recommend deciding what you need the test to answer before selecting a panel or preparation plan.
Follow the specific instructions
Our team confirms fasting, timing and medicine instructions for the exact tests booked; do not stop prescribed medicines unless your clinician tells you to.
Put the result in context
A result is interpreted alongside symptoms, history, medicines and, where needed, earlier results rather than in isolation.
Agree the next step
The next step may be reassurance, repeat testing, a GP review, treatment monitoring or specialist assessment depending on the clinical picture.
Frequently Asked Questions
References
- [1]Lee L et al. Preparation for blood tests: what can go wrong before the sample reaches the lab. Australian Prescriber. 2025. DOI: 10.18773/austprescr.2025.034.
- [2]Newsome PN et al. Guidelines on the management of abnormal liver blood tests. Gut. 2018;67:6-19. DOI: 10.1136/gutjnl-2017-314924.
- [3]Li A et al. Patterns of follow-up testing of abnormal eGFR and UACR for the detection of chronic kidney disease in Australian primary care. BMJ Open. 2025. DOI: 10.1136/bmjopen-2024-096730.
- [4]Soh SB, Aw TC. Laboratory testing in thyroid conditions: pitfalls and clinical utility. Annals of Laboratory Medicine. 2019;39:3-14. DOI: 10.3343/alm.2019.39.1.3.
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