Blood Test Results Explained Simply
A plain-language guide to reading the actual report your pathology lab gives you
Anatomy of a Blood Test Report
Every pathology report follows a similar layout, whether it comes from Laverty, QML, Melbourne Pathology, or any other provider. Here is what a typical report looks like, broken into its key parts.
Patient Details
Your name, date of birth, sex, and the requesting doctor. Always check these are correct - wrong patient details mean the results may not be yours.
Collection Date
When the blood was drawn. This is different from the report date (when the lab finished analysing). Results are relevant to the collection date.
Test Panel Name
The group of tests your doctor ordered (e.g., "Full Blood Count", "Lipid Panel"). Each panel contains several individual markers grouped together.
Individual Markers
Each row is a single measurement. The marker name (often abbreviated) appears first, followed by your result value.
Reference Range
The expected range for a healthy person of your age and sex. Your result is compared against this range to determine if it is normal, high, or low.
Flags
Letters or symbols next to your result indicating it falls outside the reference range. The most common flags are H (High), L (Low), and * (Abnormal).
What the Flags Mean
Flags appear in a column next to your results. Different laboratories use different symbols, but they all mean the same thing: your result is outside the expected range.
| Flag | Meaning | What It Tells You |
|---|---|---|
H | High | Your result is above the upper limit of the reference range. |
L | Low | Your result is below the lower limit of the reference range. |
* | Abnormal | Result falls outside the normal range. Used by some labs instead of H or L. |
** | Critical | Result is significantly outside the normal range and may require urgent attention. |
A | Abnormal | Alternative flag for abnormal results used by certain pathology providers. |
C | Critical | Alternative flag for critical results. Your doctor may have already been notified. |
(blank) | Normal | No flag means your result is within the expected reference range. |
Common Abbreviations Decoder
Blood test reports are full of abbreviations. Here is what they all stand for, grouped by category.
Full Blood Count (FBC / CBC)
| FBC | Full Blood Count (also called CBC) |
| CBC | Complete Blood Count (same as FBC) |
| Hb / Hgb | Haemoglobin |
| RBC | Red Blood Cell Count |
| WBC / WCC | White Blood Cell Count |
| Plt | Platelet Count |
| MCV | Mean Corpuscular Volume (red cell size) |
| MCH | Mean Corpuscular Haemoglobin |
| MCHC | Mean Corpuscular Haemoglobin Concentration |
| RDW | Red Cell Distribution Width |
| Hct / PCV | Haematocrit / Packed Cell Volume |
| MPV | Mean Platelet Volume |
| Retics | Reticulocyte Count |
White Cell Differential
| Neut | Neutrophils |
| Lymph | Lymphocytes |
| Mono | Monocytes |
| Eos | Eosinophils |
| Baso | Basophils |
Kidney Function
| eGFR | Estimated Glomerular Filtration Rate |
| Cr / Creat | Creatinine |
| BUN | Blood Urea Nitrogen |
| Na | Sodium |
| K | Potassium |
| Cl | Chloride |
| CO2 / HCO3 | Bicarbonate |
| Ca | Calcium |
| Mg | Magnesium |
| PO4 | Phosphate |
Liver Function
| ALT | Alanine Aminotransferase (also SGPT) |
| AST | Aspartate Aminotransferase (also SGOT) |
| GGT | Gamma-Glutamyl Transferase |
| ALP | Alkaline Phosphatase |
| Bili / TBili | Bilirubin (Total) |
| DBili | Direct (Conjugated) Bilirubin |
| Alb | Albumin |
| TP | Total Protein |
| LDH | Lactate Dehydrogenase |
Lipids (Cholesterol)
| TC | Total Cholesterol |
| LDL | Low-Density Lipoprotein ("bad" cholesterol) |
| HDL | High-Density Lipoprotein ("good" cholesterol) |
| TG / Trig | Triglycerides |
| VLDL | Very Low-Density Lipoprotein |
| Lp(a) | Lipoprotein(a) |
| ApoB | Apolipoprotein B |
Diabetes & Blood Sugar
| HbA1c | Glycated Haemoglobin (3-month glucose average) |
| FBG / FPG | Fasting Blood Glucose / Fasting Plasma Glucose |
| RBG | Random Blood Glucose |
| OGTT | Oral Glucose Tolerance Test |
Thyroid Function
| TSH | Thyroid Stimulating Hormone |
| FT4 | Free Thyroxine |
| FT3 | Free Triiodothyronine |
| TPOAb | Thyroid Peroxidase Antibodies |
| TgAb | Thyroglobulin Antibodies |
Iron Studies
| Fe | Serum Iron |
| Ferritin | Ferritin (iron stores) |
| TIBC | Total Iron Binding Capacity |
| Tsat / TS% | Transferrin Saturation |
| Tf | Transferrin |
Vitamins & Minerals
| Vit D / 25-OH | 25-Hydroxyvitamin D |
| B12 | Vitamin B12 (Cobalamin) |
| Folate | Folate (Vitamin B9) |
| Zn | Zinc |
| Cu | Copper |
| Se | Selenium |
Hormones
| Testo | Testosterone |
| E2 | Estradiol (Oestradiol) |
| FSH | Follicle Stimulating Hormone |
| LH | Luteinising Hormone |
| DHEA-S | Dehydroepiandrosterone Sulfate |
| SHBG | Sex Hormone Binding Globulin |
| Prolactin | Prolactin |
| PSA | Prostate-Specific Antigen |
| AMH | Anti-Mullerian Hormone |
Inflammation & Immune
| CRP | C-Reactive Protein |
| hsCRP | High-Sensitivity C-Reactive Protein |
| ESR | Erythrocyte Sedimentation Rate |
| ANA | Antinuclear Antibodies |
| RF | Rheumatoid Factor |
| IgE | Immunoglobulin E |
Coagulation
| INR | International Normalised Ratio |
| PT | Prothrombin Time |
| APTT | Activated Partial Thromboplastin Time |
| D-dimer | D-dimer (fibrin degradation fragment) |
Other Common
| CK / CPK | Creatine Kinase |
| UA | Uric Acid (Urate) |
| BNP / NT-proBNP | B-type Natriuretic Peptide (heart failure marker) |
| CEA | Carcinoembryonic Antigen |
| AFP | Alpha-Fetoprotein |
| Hcy | Homocysteine |
Understanding Reference Ranges
The reference range is the range of values expected in a healthy person. It is printed next to each result (e.g., “4.0 - 11.0”). Understanding how these ranges work will help you interpret your results more confidently.
What “normal” actually means
Reference ranges are calculated from 95% of healthy people. That means 5% of perfectly healthy people will naturally fall outside the range. One abnormal result does not automatically mean something is wrong.
Why ranges differ between labs
Each laboratory uses different equipment, reagents, and reference populations. A creatinine range might be 60-110 µmol/L at one lab and 55-105 µmol/L at another. Always compare results from the same lab over time.
Age and sex adjustments
Some markers have different ranges for men and women (like haemoglobin and ferritin), or for different age groups (like ALP in children). Your report should show the range appropriate for you.
Outside the range is not always bad
An eGFR of 88 when the range starts at 90 is almost certainly fine. How far outside the range matters more than whether you are outside it. A result twice the upper limit is very different from one that is 2% above it.
Units of Measurement Explained
The units column tells you how the marker is being measured. You do not need to memorise these, but understanding the basics helps when comparing results across labs or countries.
| Unit | Stands For | Plain English |
|---|---|---|
| mmol/L | Millimoles per litre | A measure of substance concentration. Used for electrolytes, glucose, cholesterol. |
| µmol/L | Micromoles per litre | One-thousandth of a millimole. Used for bilirubin, creatinine, uric acid. |
| nmol/L | Nanomoles per litre | One-millionth of a millimole. Used for hormones (testosterone, vitamin D, cortisol). |
| pmol/L | Picomoles per litre | One-billionth of a millimole. Used for thyroid hormones (Free T4, Free T3). |
| g/L | Grams per litre | Weight of substance per litre. Used for albumin, total protein, haemoglobin (some labs). |
| g/dL | Grams per decilitre | Weight per 100mL. Common in US labs for haemoglobin. 1 g/dL = 10 g/L. |
| mg/L | Milligrams per litre | Used for CRP, some vitamins. 1000x smaller than g/L. |
| mg/dL | Milligrams per decilitre | Common in US labs for glucose, cholesterol. Australian labs typically use mmol/L. |
| IU/L | International Units per litre | Measures biological activity of enzymes. Used for liver enzymes (ALT, AST, GGT). |
| U/L | Units per litre | Similar to IU/L. Used for ALP, CK, LDH, and other enzymes. |
| mIU/L | Milli-international Units per litre | One-thousandth of an IU. Used for TSH. |
| % | Percentage | Proportion of a whole. Used for HbA1c, haematocrit, transferrin saturation. |
| x10⁹/L | Billions per litre | Count of cells. Used for white blood cells and platelets. |
| x10¹²/L | Trillions per litre | Count of cells. Used for red blood cells. |
| fL | Femtolitres | Volume of a single cell. Used for MCV (red blood cell size). Normal is about 80-100 fL. |
| pg | Picograms | Weight of substance in one cell. Used for MCH (haemoglobin per red blood cell). |
| µg/L | Micrograms per litre | Used for ferritin, some vitamins. 1 µg = 0.001 mg. |
| mm/hr | Millimetres per hour | How fast red blood cells settle. Used only for ESR (Erythrocyte Sedimentation Rate). |
| seconds | Seconds | Time for blood to clot. Used for PT, APTT coagulation tests. |
| ratio | Ratio (no unit) | A calculated comparison. Used for INR, albumin/globulin ratio, TC/HDL ratio. |
Reading Multiple Test Dates
Some reports show results from multiple dates side by side in columns, letting you see how your values have changed over time. This is one of the most useful features of a blood test report.
Spotting Trends
Look at the direction of change, not just whether a value is flagged. A cholesterol reading moving from 6.2 to 5.8 to 5.1 over three tests shows excellent progress, even if 5.1 is still slightly above range.
Column Order
The most recent result is usually in the leftmost column or the first column after the marker name. Check the date headers at the top of each column to be sure.
Arrows on Reports
Some labs print arrows or delta symbols showing the direction of change from the previous test. An up arrow means the value increased; a down arrow means it decreased.
Same Lab Matters
Multi-date columns are most meaningful when all tests were done at the same lab. If you switched labs, small differences in values may be due to different analysers rather than actual health changes.
What to Do With Your Results
Do not panic
A single abnormal flag does not mean you are sick. Many results are influenced by temporary factors like what you ate, how hydrated you were, or whether you exercised that morning.
Look at patterns, not individual numbers
A mildly elevated liver enzyme on its own is less meaningful than three liver enzymes all being elevated together. Clusters of related abnormalities tell a stronger story than isolated flags.
Compare with previous results
Is this value trending up, down, or staying stable? A slowly rising HbA1c over two years is more significant than a one-off slightly elevated reading. Trends are everything.
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5 Common Misunderstandings
These misconceptions cause unnecessary worry. Understanding them will help you read your results with more confidence and less anxiety.
Myth: “One abnormal result means I am sick”
Reality: Not necessarily. A single result outside the range can be caused by dehydration, recent exercise, a meal, stress, or even the time of day. Your doctor looks at patterns, not isolated numbers.
Myth: “The reference range is the ideal range”
Reality: The reference range covers 95% of healthy people. Being at the edge of "normal" is still normal. Optimal ranges for some markers (like vitamin D or ferritin) may be narrower than the lab range.
Myth: “All labs use the same reference ranges”
Reality: Different labs use different analysers, reagents, and populations to calculate ranges. A result of 45 might be flagged at one lab but not another. Always compare results within the same lab when tracking trends.
Myth: “I should understand every single marker”
Reality: Focus on the flagged markers first. Your doctor ordered specific panels for a reason. The unflagged markers are doing fine. If you want to learn more, upload to SmarterBlood for plain-language explanations.
Myth: “My results should not change from test to test”
Reality: Blood values naturally fluctuate. This is called biological variation. Your haemoglobin can vary by 5-7% between tests. White blood cells can change by 10-15% day to day. Trends over multiple tests matter more than any single reading.
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