Understanding Your Blood Test Report
Receiving a page of numbers, abbreviations, and reference ranges from your pathology lab can feel overwhelming. But learning to read your blood test results doesn't require a medical degree — it requires knowing what each marker measures, what the reference ranges mean, and when to be concerned. This guide breaks down the most common blood tests ordered in Australia and explains exactly what each result means for your health.
The Anatomy of a Blood Test Report
Every pathology report in Australia follows a similar structure. Understanding the layout helps you navigate results quickly:
- Test name: The specific marker being measured (e.g., "Haemoglobin" or "TSH")
- Your result: The measured value from your sample
- Units: The measurement unit (e.g., g/L, mmol/L, nmol/L)
- Reference range: The expected range for a healthy person of your age and sex
- Flag: An H (high) or L (low) indicator if your result falls outside the reference range
Important: A result flagged as "high" or "low" doesn't necessarily mean something is wrong. Reference ranges represent where 95% of the population falls, meaning 5% of perfectly healthy people will have a result outside the range on any given test.
Full Blood Count (FBC / CBC)
The full blood count is the most commonly ordered blood test. It evaluates the cellular components of your blood and can detect a wide range of conditions from anaemia to infection.
Haemoglobin (Hb)
Haemoglobin is the protein in red blood cells that carries oxygen. It's one of the most important markers on your FBC.
- Normal range (men): 130–170 g/L
- Normal range (women): 120–150 g/L
- Low: May indicate iron deficiency anaemia, chronic disease, blood loss, or nutritional deficiency
- High: Can result from dehydration, smoking, living at altitude, or conditions like polycythaemia. In TRT patients, elevated haemoglobin is a common side effect requiring monitoring
Haematocrit (HCT / PCV)
Haematocrit measures the percentage of your blood volume occupied by red blood cells. It closely tracks haemoglobin and is particularly important for TRT monitoring.
- Normal range (men): 0.40–0.50 (40–50%)
- Normal range (women): 0.36–0.44 (36–44%)
- TRT concern: Haematocrit above 0.54 (54%) significantly increases the risk of blood clots and cardiovascular events. Regular blood donation can help manage elevated levels
White Blood Cell Count (WBC)
White blood cells are your immune system's soldiers. The WBC count provides a snapshot of immune activity.
- Normal range: 4.0–11.0 × 10⁹/L
- High (leukocytosis): Usually indicates infection, inflammation, stress, or rarely leukaemia
- Low (leukopenia): May suggest viral infection, autoimmune conditions, or bone marrow disorders
Platelets
Platelets are cell fragments essential for blood clotting.
- Normal range: 150–400 × 10⁹/L
- Low (thrombocytopenia): Increased bleeding risk — causes include viral infections, medications, liver disease, or autoimmune conditions
- High (thrombocytosis): May be reactive (from infection or inflammation) or indicate a bone marrow disorder
Liver Function Tests (LFTs)
Liver function tests assess how well your liver is working and whether it's been damaged. They're routinely ordered as part of health checks and are essential for anyone taking medications metabolised by the liver.
ALT (Alanine Aminotransferase)
ALT is the most specific marker for liver cell damage.
- Normal range: 5–40 U/L
- Elevated: Liver inflammation from alcohol, fatty liver disease, medications, viral hepatitis, or strenuous exercise
AST (Aspartate Aminotransferase)
AST is found in the liver, heart, and muscles, making it less specific than ALT.
- Normal range: 5–40 U/L
- Elevated: Similar causes to ALT, but also rises after heavy exercise or muscle damage. The AST:ALT ratio can help differentiate causes
GGT (Gamma-Glutamyl Transferase)
GGT is particularly sensitive to alcohol consumption and bile duct issues.
- Normal range: 5–50 U/L (men), 5–35 U/L (women)
- Elevated: Alcohol use, medications, bile duct obstruction, fatty liver, or diabetes
ALP (Alkaline Phosphatase)
- Normal range: 30–110 U/L
- Elevated: Bone disorders, bile duct obstruction, or liver disease. Can be naturally higher during bone growth (adolescents) and pregnancy
Bilirubin
Bilirubin is a byproduct of red blood cell breakdown, processed by the liver.
- Normal range: 2–20 μmol/L
- Elevated: Liver disease, bile duct blockage, or benign conditions like Gilbert's syndrome (affects ~5% of the population)
Kidney Function Tests (UEC / EUC)
The urea, electrolytes, and creatinine panel assesses kidney function and electrolyte balance.
Creatinine and eGFR
Creatinine is a waste product from muscle metabolism, filtered by the kidneys. The eGFR (estimated glomerular filtration rate) is calculated from creatinine and provides a better estimate of actual kidney function.
- Creatinine normal range: 60–110 μmol/L (men), 45–90 μmol/L (women)
- eGFR > 90: Normal kidney function
- eGFR 60–89: Mildly reduced (common in older adults, often not clinically significant)
- eGFR < 60: Moderately reduced — requires further investigation
Sodium, Potassium, and Chloride
Electrolytes are essential for nerve function, muscle contraction, and fluid balance.
- Sodium: 135–145 mmol/L (low = dehydration, medications; high = dehydration, excessive salt)
- Potassium: 3.5–5.0 mmol/L (abnormal levels can affect heart rhythm — critical to monitor)
Lipid Panel (Cholesterol)
The lipid panel measures fats in your blood and assesses cardiovascular risk.
Total Cholesterol
- Desirable: < 5.5 mmol/L
- Borderline high: 5.5–6.5 mmol/L
- High: > 6.5 mmol/L
LDL Cholesterol ("Bad" Cholesterol)
- Optimal: < 2.0 mmol/L (for high-risk individuals)
- Desirable: < 3.4 mmol/L
- High: > 4.1 mmol/L
HDL Cholesterol ("Good" Cholesterol)
- Low risk: > 1.0 mmol/L (men), > 1.3 mmol/L (women)
- Protective: > 1.5 mmol/L
Triglycerides
- Normal: < 1.7 mmol/L (fasting)
- High: > 2.0 mmol/L — associated with increased cardiovascular risk and metabolic syndrome
Thyroid Function Tests
Thyroid hormones regulate metabolism, energy, and body temperature. The TSH (thyroid-stimulating hormone) test is the primary screening tool.
TSH
- Normal range: 0.4–4.0 mIU/L
- High TSH: Suggests hypothyroidism (underactive thyroid) — your pituitary is working harder to stimulate a sluggish thyroid
- Low TSH: Suggests hyperthyroidism (overactive thyroid) — the thyroid is producing too much hormone, so the pituitary backs off
Free T4 and Free T3
If TSH is abnormal, free T4 and T3 are tested to confirm and classify the thyroid disorder.
- Free T4 normal: 10–20 pmol/L
- Free T3 normal: 3.5–6.5 pmol/L
Iron Studies
Iron studies are crucial for investigating fatigue, which is one of the most common reasons people get blood tests.
Ferritin
Ferritin reflects your body's iron stores and is the most useful single marker for iron status.
- Normal range: 30–300 μg/L (men), 20–200 μg/L (women)
- Low (< 30): Depleted iron stores, likely iron deficiency — even if haemoglobin is still normal
- Very high (> 500): Can indicate inflammation, liver disease, or iron overload (haemochromatosis)
Transferrin Saturation
- Normal: 20–50%
- Low: Iron deficiency
- High (> 45%): May suggest iron overload — genetic testing for haemochromatosis may be warranted
Blood Glucose and HbA1c
Fasting Glucose
- Normal: 3.5–5.5 mmol/L
- Impaired (pre-diabetes): 5.6–6.9 mmol/L
- Diabetes: ≥ 7.0 mmol/L on two occasions
HbA1c
HbA1c measures your average blood sugar over the past 2–3 months, providing a more reliable picture than a single fasting glucose.
- Normal: < 5.7% (< 39 mmol/mol)
- Pre-diabetes: 5.7–6.4% (39–47 mmol/mol)
- Diabetes: ≥ 6.5% (≥ 48 mmol/mol)
Vitamin D
Vitamin D deficiency is extremely common in Australia, particularly during winter months and in people who work indoors.
- Deficient: < 50 nmol/L
- Adequate: 50–150 nmol/L
- Optimal: 75–150 nmol/L (some practitioners prefer 100+)
- Toxic: > 250 nmol/L (rare, usually from excessive supplementation)
How BloodTrack Makes Sense of Your Results
Instead of deciphering a flat PDF from your pathology lab, BloodTrack transforms your blood test results into visual, trackable trends. Upload or manually enter your results to:
- See colour-coded markers — instantly know what's in range, borderline, or flagged
- Track trends over time — a single result is just a snapshot; your trend tells the real story
- Spot correlations — see how markers relate to each other (e.g., ferritin dropping as haemoglobin stays stable may predict future anaemia)
- Prepare for GP visits — share a clear visual summary instead of trying to remember numbers
Knowledge is power. Understanding your blood test results puts you in the driver's seat of your own health.
