Lab results
How to read your blood test results
Select the markers from your blood test, enter your values, and get a plain-language explanation to discuss with your doctor.
Add your markers and values, then choose “Explain my results” to see a plain-language readout for each.
How to read your blood test results
Every result on a blood test report has three parts: a value (the number measured), a unit (such as mg/dL or mmol/L), and a reference range — the band of values the lab considers typical. To read a result, you compare its value against that range. A result flagged “high” or “low” simply sits outside the lab’s range; on its own it is not the same thing as a problem. Reference ranges also vary from one lab to another and shift with age and sex, so the same value can be inside the range at one lab and just outside it at another.
What “reference range” and “normal” actually mean
A reference range is built by measuring a marker in a large group of healthy people and taking the middle band — usually the central 95% of their results. That design has a side effect worth understanding: by definition, about 1 in 20 perfectly healthy people will fall outside the range on any given test. So a value just outside the range is common and often means nothing on its own. A flagged result is best treated as a prompt to ask a question, not as a diagnosis.
What this tool covers — 25 common blood markers
This explainer covers 25 of the markers that show up most often on routine blood panels — the ones people are most likely to want explained after a check-up. Pick the markers that appear on your own report and skip the rest.
How the explainer works
Choose the markers you want to understand, type in your values, and add your own lab’s reference range if your report lists one (otherwise we use a standard adult range). You then get a plain-language read for each marker — whether it sits below, within, or above range, and what that generally means — grounded in a reviewed dataset. The tool is free to use, and it stores nothing: your values are not saved after you close the page.
Is this a diagnosis?
No. This tool explains and gives context to your numbers in everyday language. It does not diagnose any condition, and it never recommends treatment, medication, or dosing. A value outside the reference range is not the same as having a disease, and a value inside the range does not rule one out. Always confirm what your results mean with a clinician who knows your history.
How we built this
The reference ranges behind this tool come from a reviewed internal dataset, cross-checked against authoritative clinical sources including Mayo Clinic Laboratories, MedlinePlus (NIH), Cleveland Clinic, and ARUP Laboratories. The ranges are standard adult values; your own lab’s range may differ, which is why you can enter it. This content was last reviewed in June 2026.
Frequently asked questions
Does this diagnose conditions?
No. It explains your values in plain language for information only; it never diagnoses or recommends treatment. Always discuss results with your doctor.
Where do the reference ranges come from?
From a reviewed internal dataset of standard adult ranges. Your own lab's range may differ — you can enter it to override the default.
What do high or low blood test results mean?
A high or low result means the value falls outside the lab’s reference range. That can flag something worth checking, but it can also be normal variation, recent food or exercise, or a lab difference. Interpret it with a clinician.
What is a normal blood test result?
A “normal” result sits inside the reference range — the band of values typical for healthy adults at that lab. Ranges vary by lab, age, and sex, so “normal” is defined against the range printed on your own report.
Should I worry about one result outside the range?
Usually not on its own. About 1 in 20 healthy people fall outside a range by chance, and many values drift with diet, timing, or illness. A single flagged result is a reason to ask your doctor, not to panic.
Can this tool replace seeing a doctor?
No. It adds plain-language context to your numbers, but it cannot examine you, know your history, or diagnose. Use it to prepare better questions, then confirm anything that concerns you with a clinician.