Understanding test results
Understanding your test results:ask what the number changes.
A laboratory result is useful only when you know why the test was ordered and what the result changes. Reference ranges, previous values, medicines and symptoms all affect interpretation.
Start by asking what the test was meant to answer.
A test result only makes sense in relation to the question that led to testing. One blood result may help assess anaemia, thyroid disease, diabetes risk, kidney function or another specific issue. It cannot answer every health concern at once.
The NHS explains that blood tests are used for different purposes, including checking general health, helping diagnose conditions, assessing risk and monitoring treatment. [1]
The most useful first question is not “Is this high or low?” but “Why was this test ordered, and what decision could the result change?”
A normal result may make the condition being tested for less likely.
An abnormal result may need repeat testing, another test or no action, depending on the pattern.
What does a laboratory reference range mean?
A reference range is a guide based on the laboratory's method and reference population. It is not a perfect line between healthy and ill.
Manchester University NHS Foundation Trust explains that ranges can vary with the method and units and that age, sex, pregnancy, time of sampling and other factors may affect interpretation. [2]
Use the range printed on your own report. Comparing your result with a random internet range from another laboratory can be misleading.
How abnormal is the result?
The degree of change matters. A result that is just outside the laboratory range may have a different meaning from a result that is markedly abnormal, especially when previous results are available.
Ask whether the result is new, whether it has changed over time and whether there are medicines, illness, hydration or timing factors that could affect it.
Do not change treatment from a portal flag alone. A red or highlighted value is an invitation to interpret the result, not a diagnosis.
When does a result need repeating?
Some results are repeated because the first result was unexpected, borderline, taken at the wrong time or affected by a temporary factor. Others need confirmation before a diagnosis or treatment decision.
Repeat testing should have a reason. Ask whether the same test needs to be repeated, whether a different test is more useful and how long the clinician expects the underlying biology to take before a change would be meaningful.
Repeating too soon can measure normal day-to-day variation rather than a real clinical change.
Seven questions to ask about a test result
- Why was this test ordered?
- What does the result make more or less likely?
- How far is it from the laboratory's reference information?
- Could medicines, timing, illness or another factor affect it?
- Does it need to be repeated or confirmed?
- What changes if the result is acted on?
- What should happen if my symptoms continue even if this result is normal?
These questions help move the discussion from one isolated number to a clinical decision.
What if the test is normal but you still feel unwell?
A normal test does not mean symptoms are imaginary. It means the result did not show the abnormality that test was designed to detect at that time.
The next step may be to review the original question, reconsider the symptom pattern, check medicines, examine another system, monitor change over time or decide that another test is justified.
Do not keep adding tests simply until one becomes abnormal. Further testing should still have a defined purpose.
Normal is information, not dismissal.
Ask what has become less likely, what remains unexplained and what should trigger reassessment.
How are results discussed in Dr Stavy's published workflow?
The next appointment is used to discuss test results and your personalised plan, including questions, concerns and next steps. Follow-up is also used to review progress and make adjustments as required. [3]
Ask when your results and plan are expected and how many follow-up appointments may be useful. No fixed turnaround or standard number of appointments is stated here.
For the wider testing decision, see the functional medicine testing and diagnostics page. For the overall consultation sequence, see the first functional medicine consultation.
Some results need earlier clinical contact.
If a clinician or laboratory tells you a result needs urgent review, follow that instruction rather than waiting for a routine follow-up. If you are acutely unwell, use the appropriate NHS urgent or emergency route based on your symptoms.
Different tests and conditions have different escalation rules. There is no single urgent threshold that applies to all blood tests.
Keep the full report, not only the highlighted value.
The full report contains the test name, units, laboratory reference information and often comments that help another clinician understand the result. Screenshots can omit this context.
If you are sharing a result with another doctor, send the full report where possible. Also provide the date, the reason the test was ordered and any relevant medicine or treatment change.
Keep results together so the trend is easier to read
Keep the full report with the date. If the same test is repeated later, bring both reports. A trend can be useful, but only when the tests and timing are comparable.
Write down any medicine or treatment change that happened between tests. Also note a major illness if it may have affected the result. This can help the clinician decide whether a change is meaningful.
Do not focus only on values marked in red. A normal value can be important, and an abnormal value may be minor or temporary. The clinical question, symptoms and past results give the number its meaning.
One result is only one point in time.
A result can be more useful when it is compared with an earlier value, especially when the same test, units and clinical question are being followed. A change does not always mean a condition is better or worse. Timing, treatment, illness and laboratory method can affect some results.
Ask whether the result needs repeat testing, whether the trend matters, and when another check would change the plan. Do not repeat a test simply because a number is outside the reference range without first understanding why it is being followed.
What patients say about the consultation experience.
Patient reviews can help you understand how a consultation feels. They do not prove that a diagnosis will be found or that a treatment will work.
Individual reviews reflect personal experiences and do not predict diagnosis, treatment response or outcome.
“patient, understanding and kind”
Google reviewer
“warm and compassionate bedside manner”
Google reviewer
“takes incredible care to get to know her patients”
Google reviewer
Common questions
What does a result outside the reference range mean?
It means the result is outside the laboratory's reference information, not that you automatically have a disease. The meaning depends on how far the result has changed, your symptoms, previous values, medicines, timing and the laboratory method. Some results need repeat testing or a different test before a diagnosis is made.
Can a normal blood test rule out illness?
No single normal test rules out every illness. A normal result can make the condition that test was designed to assess less likely, but it cannot answer a question the test does not measure. If symptoms continue, ask what remains unexplained and whether reassessment is needed.
Why do reference ranges differ between laboratories?
Laboratories may use different methods, units and reference populations. Patient factors such as age, sex, pregnancy and timing can also matter. Use the range printed on your own report and ask the clinician to interpret it in context rather than comparing it with a generic internet range. [2]
When should a blood test be repeated?
Repeat testing can be useful when a result is unexpected, borderline, affected by timing, or needs confirmation before a decision. The interval depends on the test and clinical question. Repeating too soon may measure normal variation rather than a meaningful change.
What should I ask when a test result is abnormal?
Ask why the test was ordered, how abnormal the result is, whether medicines or timing affect it, whether it needs confirmation, what diagnosis becomes more or less likely, and what changes in the plan. A flagged number should lead to interpretation, not an automatic treatment change.
How does Dr Stavy discuss test results?
A follow-up appointment can be used to discuss test results and your personalised plan, answer questions and agree next steps. Ask when to expect your results and when to return; no fixed turnaround or standard follow-up interval is stated for everyone. [3]
Medical sources and further reading
- NHS: Blood tests. Explains why blood tests are used and why different tests answer different questions.
- Manchester University NHS Foundation Trust: Reference ranges. Explains that reference ranges are guides and can vary with method, units and patient factors.
- Dr Stavy Experience Input EI006: follow-up discussion of results, plan and next steps. Owner-adopted operational source for the practice's result-review and follow-up workflow.
A result is one part of the clinical picture.
Ask why the test was ordered, what has changed, and what the next decision should be.