Understanding your blood test results

Test results are information, not verdicts. A value slightly outside a reference range is often normal for that person, and a normal value does not always rule out a problem. Results should be interpreted alongside your symptoms and history.

Full blood count

Measures red cells, white cells and platelets. Low haemoglobin suggests anaemia, which has many causes including iron deficiency, infection, chronic disease and heavy periods. Raised white cells can point to infection or inflammation. Platelets affect clotting.

Blood sugar and HbA1c

A fasting blood sugar reflects a single moment. HbA1c reflects average glucose over roughly three months, so it is used to diagnose and monitor diabetes. If you have diabetes, your clinician will set a personal target rather than applying one number to everyone.

Kidney function

Creatinine, urea and an estimated filtration rate indicate how well the kidneys are clearing waste. Results can be affected by hydration, muscle mass and some medicines, so trends over time matter more than one reading.

Liver function

Enzymes such as ALT and AST, plus bilirubin and albumin, reflect liver health. Mild changes are common and can follow infections, alcohol, some medicines, or fatty liver. Persistent abnormalities need follow-up.

Lipid profile

Total cholesterol, LDL, HDL and triglycerides are used alongside blood pressure, smoking status, age and family history to estimate cardiovascular risk. Treatment decisions follow overall risk, not one number in isolation.

Other common tests

• Thyroid function: investigated for fatigue, weight change, palpitations or mood change
• Malaria test: confirms or excludes parasites in a febrile illness
• Urinalysis: checks for infection, blood, protein and sugar
• HIV, hepatitis and syphilis testing: offered routinely in several situations, with counselling

Reading the report

Reference ranges vary between laboratories, so compare against the range printed on your own report. Flags marked high or low are prompts for a clinician to consider, not diagnoses. Where possible, repeat tests at the same laboratory so results are comparable.

Questions to ask about any result

• What does this test measure, and why was it ordered?
• Does this result change anything in my care?
• Does it need repeating, and when?
• Could any of my medicines or recent illness have affected it?
• Can I have a copy for my records?

Keep your results together. A history of readings over time is far more useful to any clinician than a single sheet of paper.