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NHS Blood Test Results Explained: What Your NHS Lab Report Means

NHS lab reports use different abbreviations, ranges, and reporting formats to US labs. This guide explains the most common NHS blood test panels — FBC, U&Es, LFTs, TFTs — and what each value means, in plain language.

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The Four Core NHS Blood Test Panels

NHS GPs most commonly order four core blood panels — FBC, U&Es, LFTs, and TFTs — as the first-line investigation for most symptoms. Each panel groups related tests that are processed together at the NHS trust's clinical biochemistry laboratory.

Key Difference: NHS Flags vs Optimal Ranges

NHS reference ranges are calculated from large UK population samples — they represent the 'not flagged' threshold, not the optimal range for health. A result within the NHS reference range can still be suboptimal. For example, the NHS lower normal for ferritin in women is 12 ng/mL — but research consistently shows symptoms of iron deficiency are common below 50 ng/mL.

NHS AbbreviationFull NameWhat It Tests
FBCFull Blood CountRed cells (Hb, haematocrit, MCV, MCH, MCHC, RBC), white cells (WBC differential), platelets
U&EsUrea and ElectrolytesSodium, potassium, urea, creatinine, eGFR — kidney function and electrolytes
LFTsLiver Function TestsALT, AST, ALP, GGT, bilirubin, albumin, total protein
TFTsThyroid Function TestsTSH; free T4 if TSH is abnormal
HbA1cGlycated haemoglobinAverage blood glucose over 3 months — diabetes screen and monitoring
Lipid profileFasting lipidsTotal cholesterol, LDL, HDL, triglycerides, non-HDL cholesterol
ESRErythrocyte sedimentation rateNon-specific inflammation marker — often ordered with CRP

UK vs US Units: Key Differences

NHS results often use different units to US labs, which can cause confusion when comparing to online reference ranges. Glucose in the UK is reported in mmol/L (1 mmol/L = 18 mg/dL). Cholesterol in the UK is in mmol/L (1 mmol/L = 38.67 mg/dL). Creatinine in the UK is in µmol/L (1 µmol/L = 0.011 mg/dL). Calcium in the UK is in mmol/L (1 mmol/L = 4.0 mg/dL). When Googling reference ranges, make sure you are reading UK ranges (mmol/L) or are converting correctly.

How to Read Your NHS Lab Report

NHS lab reports use asterisks (*), H (high), or L (low) to flag abnormal results. A single asterisk typically means mildly outside the reference range; double asterisk or bold flags may indicate a more significant abnormality requiring clinical attention. "Ref range" is printed on the report — these are the laboratory's population reference ranges, not individual optimal targets. If your GP has not called you to discuss results, borderline flags are often monitored without immediate treatment. However, you are entitled to ask for a copy of all your blood test results and to discuss them at your next appointment or via NHS 111 if results concern you.

UK vs US Units — Key Differences to Know

• Glucose: NHS uses mmol/L (UK 5.5 mmol/L = US 99 mg/dL)
• Cholesterol: NHS uses mmol/L (UK 5.0 mmol/L = US 193 mg/dL)
• Creatinine: NHS uses µmol/L (UK 80 µmol/L = US 0.9 mg/dL)
• Bilirubin: NHS uses µmol/L (UK 10 µmol/L = US 0.6 mg/dL)
• Haemoglobin: NHS uses g/dL (same as US)
• Vitamin D: NHS uses nmol/L (UK 50 nmol/L = US 20 ng/mL)

Getting NHS Results Faster

NHS blood test results are increasingly available through the NHS App (requires NHS login with GP surgery registration). Results typically appear 3–7 days after the blood draw for routine tests. The NHS App allows you to view most results from your surgery's system directly — though some practices restrict online access to results until a clinician has reviewed them. If you need results faster, private UK labs (Medichecks, Thriva, Blue Horizon) provide next-day results for most standard panels at a cost of £40–£150 depending on the panel.

Medical Disclaimer

This article is for educational purposes only and does not constitute medical advice. Reference ranges, supplement dosages, and nutritional information mentioned are general educational guidance from published research—not personalised recommendations. Do not use this content to self-diagnose or self-treat any condition. Always consult a qualified healthcare provider before making any changes to your health regimen, medications, or supplements.

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