You have had your blood drawn, waited for your results, and now you are staring at a page full of abbreviations, numbers, and ranges that seem designed to confuse. You are not alone. Blood test reports can look daunting, but with a little guidance, they are actually quite straightforward to interpret. This guide walks you through the most common markers, what they measure, and what your numbers might mean.
How to Read a Blood Test Report
Every blood test result report contains three key pieces of information for each marker:
- Your result — the actual measured value from your blood sample
- The unit of measurement — e.g. mmol/L, g/dL, U/L, ng/mL
- The reference range — the range of values considered normal for healthy adults
If your result falls within the reference range, it is generally considered normal. If it falls above (marked H for High) or below (marked L for Low), it may warrant further investigation — but this does not automatically mean something is seriously wrong. Reference ranges are statistical averages based on large population studies, and individual variation is entirely normal.
Important: Never panic if a result falls slightly outside the reference range. A single result out of range, in isolation, rarely indicates serious disease. Always review results in the context of your symptoms, medical history, and other test results — ideally with a qualified clinician.
Full Blood Count (FBC) — Key Markers Explained
Haemoglobin (Hb)
Haemoglobin is the protein in red blood cells that carries oxygen around the body. Low haemoglobin indicates anaemia — which can cause fatigue, breathlessness, and dizziness. Normal ranges: Men 130–170 g/L; Women 120–150 g/L. High haemoglobin can be seen in dehydration or in certain blood disorders.
White Blood Cell Count (WBC)
White blood cells are the immune system's soldiers. A high WBC usually indicates infection or inflammation. A low WBC can indicate bone marrow suppression, viral infection, or certain medications. Normal range: 4.0–11.0 × 10⁹/L.
Platelets
Platelets control blood clotting. Low platelets (thrombocytopenia) can cause excessive bruising or bleeding. High platelets (thrombocytosis) can increase clotting risk. Normal range: 150–400 × 10⁹/L.
Diabetes Markers
Fasting Glucose
Normal fasting glucose is below 5.6 mmol/L. Pre-diabetes is indicated between 5.6–6.9 mmol/L. A result of 7.0 mmol/L or above on two separate tests confirms a diagnosis of diabetes.
HbA1c
HbA1c measures the percentage of haemoglobin coated with glucose — reflecting your average blood sugar over 2–3 months. Below 42 mmol/mol (6%) is normal. 42–47 mmol/mol indicates pre-diabetes. 48 mmol/mol (6.5%) or above is the diagnostic threshold for diabetes.
Cholesterol & Lipid Panel
Total Cholesterol
Desirable: below 5.0 mmol/L. Total cholesterol alone tells only part of the story — the ratio of LDL to HDL is equally important.
LDL Cholesterol
LDL ("bad") cholesterol deposits plaque in artery walls. Target: below 3.0 mmol/L for most people; below 2.0 mmol/L if you have existing cardiovascular disease or high risk.
HDL Cholesterol
HDL ("good") cholesterol removes plaque from arteries. Higher is better. Target: above 1.0 mmol/L for men; above 1.2 mmol/L for women.
Triglycerides
High triglycerides are associated with cardiovascular risk and often linked to diet, alcohol, and insulin resistance. Normal: below 1.7 mmol/L fasting.
Liver Function Tests
ALT (Alanine Transaminase)
ALT is released when liver cells are damaged. Elevated ALT is one of the most common abnormal results and can indicate fatty liver, alcohol damage, viral hepatitis, or medication effects. Normal: below 40–56 U/L depending on the laboratory.
Bilirubin
A breakdown product of red blood cells. Elevated bilirubin can cause jaundice and may indicate liver disease, bile duct obstruction, or haemolysis. Normal total bilirubin: below 21 μmol/L.
Kidney Function
Creatinine & eGFR
Creatinine is a waste product filtered by the kidneys. eGFR (estimated Glomerular Filtration Rate) estimates how well your kidneys are filtering blood. eGFR above 90 is normal. Values of 60–89 suggest mildly reduced function; below 60 indicates chronic kidney disease and requires further investigation.
Thyroid — TSH
TSH (Thyroid-Stimulating Hormone) is the most sensitive marker for thyroid function. High TSH usually indicates an underactive thyroid (hypothyroidism). Low TSH usually indicates an overactive thyroid (hyperthyroidism). Normal range: approximately 0.4–4.0 mIU/L, though this varies by laboratory and age.
Vitamin D
Vitamin D is measured as 25-hydroxyvitamin D. Below 25 nmol/L is classified as deficient. 25–50 nmol/L is insufficient. 50–125 nmol/L is considered optimal. Most UK adults benefit from supplementation, particularly in winter months.
What to Do If a Result is Abnormal
- Don't panic. A single abnormal value rarely means serious disease.
- Look at the degree of abnormality. Slightly outside the range is very different from markedly abnormal.
- Consider your symptoms — do the results fit with how you feel?
- Discuss with a professional. Your GP or our clinical team can review results in the context of your full medical history.
- Retest if needed. Many values fluctuate day-to-day. A follow-up test often provides clarity.
📋 Royal Saafi Reports: Every result we send includes plain-English explanations of each marker, your value, the reference range, and — where a result falls outside normal — a clear note about recommended next steps. We also flag any results that require urgent clinical attention.
Understanding your results puts you in control of your health. At Royal Saafi Healthcare, we are always available to discuss your results and answer any questions. Your health journey doesn't end when the results arrive — it begins there.