You’ve had a blood test — and now you’re looking at a results printout full of numbers, abbreviations, and reference ranges. What does it all mean? This guide explains the most common blood test results in plain language, so you can have a more informed conversation with your doctor and understand what your numbers are telling you about your health.
How to Read Blood Test Results
Most blood test results show three things:
- The test name — what was measured (e.g., haemoglobin, TSH, cholesterol)
- Your result — the measured value
- The reference range — the normal range for that test (varies by lab, age, and sex)
A result marked with H (high) or L (low) or an asterisk means it falls outside the reference range. However, a result outside the range doesn’t automatically mean there’s a problem — context matters enormously. Some people naturally have values at the edges of normal, and a single out-of-range result is very different from a pattern of abnormal results.
Complete Blood Count (CBC / FBC): What It Measures
The full blood count (FBC in Australia/UK, CBC in the US) is one of the most commonly ordered tests. It measures the cells in your blood.
Haemoglobin (Hb)
What it measures: The protein in red blood cells that carries oxygen.
Normal range: Approximately 130–180 g/L for men; 115–165 g/L for women (varies by lab)
Low Hb (anaemia): Can cause fatigue, breathlessness, dizziness, and pale skin. Causes include iron deficiency, B12 deficiency, blood loss, and chronic disease.
High Hb: Can indicate dehydration or a blood disorder such as polycythaemia vera.
White Blood Cells (WBC / WCC)
What it measures: Immune system cells
Normal range: Approximately 4–11 × 10⁹/L
High WBC: Often indicates infection, inflammation, or (rarely) blood cancer
Low WBC: Can indicate viral infection, autoimmune disease, or bone marrow problems; may be caused by certain medications
Platelets
What they do: Help blood clot
Normal range: Approximately 150–400 × 10⁹/L
Low platelets (thrombocytopenia): Can increase bleeding risk; causes include viral illness, certain medications, and immune conditions
High platelets (thrombocytosis): Can occur after infection, inflammation, or iron deficiency
Cholesterol and Lipid Panel Results Explained
A lipid panel measures fats in your blood that affect your heart disease risk.
Total Cholesterol
Desirable level: Below 5.5 mmol/L (Australia) / below 200 mg/dL (US)
What it means: A measure of all cholesterol in the blood; needs to be interpreted alongside HDL and LDL
LDL Cholesterol (“Bad” Cholesterol)
Optimal level: Below 2.0–2.6 mmol/L for people at high cardiovascular risk; under 3.4 mmol/L for lower risk
What it means: LDL carries cholesterol to artery walls, where it can build up as plaque. High LDL increases heart attack and stroke risk.
HDL Cholesterol (“Good” Cholesterol)
Optimal level: Above 1.0 mmol/L for men; above 1.3 mmol/L for women (higher is better)
What it means: HDL carries cholesterol away from artery walls. Higher HDL is protective against heart disease.
Triglycerides
Normal level: Below 1.7 mmol/L
What it means: High triglycerides are linked to metabolic syndrome, diabetes risk, and pancreatitis. Often elevated by excess alcohol, sugar, and refined carbohydrates.
Blood Sugar (Glucose) Results Explained
Fasting Glucose
Normal: 3.9–5.4 mmol/L
Pre-diabetes (impaired fasting glucose): 5.5–6.9 mmol/L
Diabetes: 7.0 mmol/L or above on two occasions
HbA1c (Glycated Haemoglobin)
Normal: Below 5.7% (39 mmol/mol)
Pre-diabetes: 5.7–6.4% (39–47 mmol/mol)
Diabetes: 6.5% or above (48 mmol/mol) on two occasions
What it measures: Average blood sugar over the past 2–3 months; unlike a single glucose test, it’s not affected by recent meals
Thyroid Function Tests (TFTs) Explained
TSH (Thyroid Stimulating Hormone)
Normal range: Approximately 0.4–4.0 mIU/L (varies by lab and age)
High TSH: Suggests the thyroid is underactive (hypothyroidism); your pituitary gland is working harder to stimulate it
Low TSH: Suggests the thyroid is overactive (hyperthyroidism); the pituitary is reducing stimulation
Free T4 and Free T3
These measure the actual thyroid hormones in circulation. They’re usually ordered alongside TSH to confirm thyroid problems and assess thyroid treatment.
Kidney Function Tests Explained
Also called Urea, Electrolytes, and Creatinine (UEC/UEL), or Basic Metabolic Panel (BMP).
Creatinine and eGFR
What they measure: How well your kidneys filter waste
Normal eGFR: Above 60 mL/min/1.73m²; 90+ is optimal
Low eGFR: Indicates reduced kidney function; may be chronic kidney disease if persistent
Liver Function Tests (LFTs) Explained
ALT and AST (Liver Enzymes)
What they measure: Enzymes that leak from damaged liver cells
Elevated ALT/AST: Indicates liver stress or damage; common causes include fatty liver disease, alcohol, medications, and viral hepatitis
Bilirubin
What it measures: Breakdown products of red blood cells processed by the liver
Elevated bilirubin: Can cause jaundice (yellowing of skin/eyes); causes include liver disease, gallstones, and haemolysis
What to Do If Your Results Are Abnormal
A result outside the reference range doesn’t always require immediate action, but it does warrant a conversation with your doctor. When reviewing your results with your GP, ask:
- “Is this result clinically significant, or borderline?”
- “What might be causing this?”
- “Do we need to retest to confirm?”
- “What are the next steps?”
- “Should I be making any lifestyle changes?”
How NORMA Can Help You Understand Your Results
Blood test results can be confusing, overwhelming, and anxiety-provoking — especially when you’re waiting to discuss them with your doctor. NORMA can help you:
- Ask questions like “What does a high TSH mean?” or “Is a haemoglobin of 118 concerning?” in plain language
- Understand the relationship between different test values
- Prepare specific, informed questions for your GP appointment
- Log your results over time to track trends
NORMA is not a replacement for your doctor’s interpretation of your results — but it’s the health companion that helps you walk into that appointment informed and ready to ask the right questions.