How to read a pathology report
Learn what a marker is and what the range next to it means. Find out why labs print different ranges and what to ask at your appointment.
These days, test results often arrive in an app. Sometimes they come before anyone has talked you through them. A flagged result and an hour of searching online can be a stressful mix.
Here’s how a clinician reads the same page.
A marker is one measurement of one thing
Cholesterol is a marker. Glycated haemoglobin is a marker. So is your blood pressure.
Each one answers a narrow question. None of them tells the whole story of your health.
A clinician sees a marker as one piece of a bigger picture. They look at it alongside your history and your symptoms. They’ll also consider an examination if one is needed.
The range next to your result isn’t a verdict
Most results are printed next to a range. Healthdirect Australia explains it simply. Reference intervals are “a range of values that are considered generally normal for the population, but not necessarily for everyone”.
The second half of that sentence is the important part. The range describes a whole population, and you’re one person.
Healthdirect also says that if your result is higher or lower than the general population’s range, “it doesn’t always mean there is a problem”.
So a flagged result is a good reason to ask a question. It doesn’t give you the answer.
Two labs can print two different ranges
The range on your report comes from the laboratory that ran your test.
Labs in Australia and New Zealand have spent years working to line up their common ranges. That work is needed because the ranges vary. A 2016 report in The Clinical Biochemist Reviews noted that laboratories “using the same analytical platform and reagents often had different RIs with no sound basis for these differences”.
In practice, this is simple. Read your result against the range printed on that same report. Take care when comparing a number from one lab with a range you found somewhere else.
Look at the trend, not one result
A single result is a snapshot. What a clinician usually wants to see is the trend.
What was your result last time? And the time before that?
A number moving steadily in one direction over three tests tells a clinician more than one result just past a cut-off. That’s also why repeating a test is often the right next step, before acting on it.
Everyday things can change your numbers
Healthdirect lists what a clinician considers when reading your result. These include the reason you had the test, your age and sex, and your overall health. They also include your lifestyle and any treatments or medicines you take, including supplements.
Everyday things can shift a result too. A recent infection, a hard week of training or a bad night’s sleep can all play a part. So can alcohol, being dehydrated, whether you fasted and the time of day your blood was taken.
Inflammation markers are especially sensitive. They can react to a cold you’ve already forgotten about.
That’s why your practitioner will ask about the two weeks before your test, as well as the test itself.
Take these five questions to your appointment
- Is this result outside the range in a way that matters for my health?
- Does it fit my symptoms, or is it a one-off finding?
- Should we repeat it before we act on it?
- What would you expect to see if this were nothing?
- What would change your mind?
If your practitioner answers the last one, you can see how they’re thinking it through.
Three things to avoid
Please don’t start or stop a medicine because of a flagged result.
Try not to compare your number with a range you found online.
Don’t put it off either. If a result has gone unexplained for months, book an appointment and ask about it.
Symptoms that need urgent care, whatever the report says
A flagged result is rarely an emergency. Some symptoms can be.
Chest pain, breathlessness, sudden weakness or numbness, confusion or heavy bleeding all need urgent in-person care, whatever any report says. Call 000.
Sources
- Healthdirect Australia. Understanding pathology tests. Reference intervals, and the factors a clinician weighs when reading a result.
- Healthdirect Australia. Full blood count (FBC). A result outside the general population’s range “doesn’t always mean there is a problem”.
- Koerbin G, Tate JR. Harmonising adult reference intervals in Australia and New Zealand: the continuing story. The Clinical Biochemist Reviews 2016;37(3):121 to 129.