Understanding the Layout

A blood test report typically shows: the test name, your result, the unit of measurement, and the reference range (the normal range for healthy adults). Results outside the reference range are usually flagged with H (high) or L (low). An asterisk (*) may indicate a result requiring attention.

ImportantBlood test results must be interpreted by a doctor in context with your symptoms, age, medications and health history. This guide explains what tests measure — it is not a substitute for medical advice. Never self-diagnose based on results alone.

Most Common Blood Tests Explained

  1. 1

    Full Blood Count (FBC / CBC)

    Tests the different cells in your blood. Key results to understand: Haemoglobin (Hb/Hgb) — carries oxygen; low = anaemia (fatigue, breathlessness). White Blood Cells (WBC) — immune cells; high may indicate infection or inflammation; very low may indicate immune suppression. Platelets — clotting; low = bruise/bleed easily; high may indicate inflammation.

  2. 2

    Lipid Panel (Cholesterol)

    Total Cholesterol: aim under 5.0 mmol/L. LDL (bad cholesterol): aim under 3.0 mmol/L (lower if you have heart disease risk factors). HDL (good cholesterol): higher is better — aim above 1.0 mmol/L. Triglycerides: aim under 2.0 mmol/L; raised by excess sugar and alcohol.

  3. 3

    Blood Glucose / HbA1c

    Fasting glucose: normal is 3.9–5.5 mmol/L. 5.6–6.9 = pre-diabetes range. 7.0+ = diabetes range. HbA1c measures average blood sugar over 3 months — more reliable than a single glucose reading. Below 48 mmol/mol (6.5%) is normal; above indicates diabetes.

  4. 4

    Kidney Function (eGFR, Creatinine, Urea)

    eGFR (estimated Glomerular Filtration Rate): measures how well kidneys filter blood. Above 90 is normal. Below 60 may indicate reduced kidney function. Creatinine: waste product filtered by kidneys; elevated if kidneys are struggling.

  5. 5

    Liver Function Tests (LFTs)

    ALT and AST: enzymes released when liver cells are damaged; elevated in liver disease, medication side effects, or alcohol. ALP: elevated in bone or liver conditions. Bilirubin: breakdown product of red blood cells; elevated causes jaundice.

  6. 6

    Thyroid Function (TSH, T4)

    TSH (Thyroid Stimulating Hormone): the most sensitive thyroid test. High TSH = underactive thyroid (hypothyroidism — fatigue, weight gain, feeling cold). Low TSH = overactive thyroid (hyperthyroidism — weight loss, anxiety, rapid heartbeat).

  7. 7

    Iron Studies

    Serum iron: the amount of iron in your blood. Ferritin: stored iron — the most useful measure of iron stores; low ferritin means iron deficiency even if serum iron looks normal. Transferrin saturation: how much of the iron-carrying protein is loaded.

Questions to ask your doctorIs my result significantly outside the range or borderline? What does this mean for me specifically? Do I need to repeat the test? Do I need treatment or just monitoring? Are there lifestyle changes that would help?

Frequently Asked Questions

H (high) or L (low) means your result falls outside the statistical reference range for healthy adults. However, reference ranges are set for 95% of the population — 5% of healthy people fall outside by definition. A slightly abnormal result may be insignificant, a lab variation, or meaningful — your doctor determines which based on the full clinical picture.
It depends on what is being tested. Fasting (nothing to eat or drink except water for 8–12 hours) is required for accurate cholesterol panels, glucose and triglyceride measurements. A full blood count, thyroid tests and most other panels do not require fasting. Your doctor or the lab will specify if fasting is needed when ordering the test.