helvy.co.uk

The Helvy Journal

Evidence-based
health guides.

No broscience. No clickbait. Every claim links to NHS, NICE, BMJ, or PubMed. Written by Helvy. Medically reviewed by GMC-registered doctors.

79

Guides

24

Categories

GMC

Reviewed

Featured guides

Longevity·18 min

The Best Blood Tests for Longevity (UK 2026)

15 science-backed biomarkers that predict biological age and healthspan — from hs-CRP and ApoB to homocysteine and DHEA-S.

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GLP-1 Medications·15 min

Blood Tests for Ozempic, Mounjaro & Wegovy Users (UK Guide 2026)

Which blood tests should you get before and during GLP-1 treatment? Liver, kidney, thyroid, metabolic and nutritional biomarkers explained.

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Getting Started·20 min

What Can a Blood Test Detect? Complete UK Guide (2026)

Everything a blood test can reveal — vitamins, hormones, thyroid, diabetes, heart disease, liver and kidney function, inflammation, and cancer screening including the Galleri trial.

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GLP-1 Medications·18 min

Blood Tests for Women on GLP-1 Drugs During Perimenopause (UK 2026)

Bone loss, muscle depletion, thyroid disruption, gallbladder risk — the compounded dangers of Ozempic + perimenopause.

Read guide

All 79 guides

Getting Started

9 guides

20 min read

What Can a Blood Test Detect? Complete UK Guide (2026)

Everything a blood test can reveal — vitamins, hormones, thyroid, diabetes, heart disease, liver and kidney function, inflammation, and cancer screening including the Galleri trial.

14 min read

Fasting Blood Test UK: Which Tests, How Long & What You Can Drink (2026)

Which blood tests require fasting, how long to fast, what you can drink, and what happens if you accidentally eat beforehand.

12 min read

The Complete Guide to Blood Tests for Men (UK 2026)

Everything you need to know about blood testing — what gets tested, why it matters, and what your results actually mean.

14 min read

Private Blood Tests UK: How Much Do They Cost in 2026?

A clear breakdown of private blood test costs in the UK — prices by test type, what the NHS covers for free, and hidden costs to avoid.

15 min read

How Often Should You Get a Blood Test? UK Guide (2026)

Evidence-based testing schedules for healthy adults, athletes, and those managing conditions. NHS Health Check frequency vs private testing.

16 min read

Full Body Blood Test UK: What Gets Tested, Costs & Where to Get One (2026)

What 50+ biomarkers reveal, NHS Health Check vs private panels, how to read results, and how to choose the right test for your goals.

14 min read

How to Read Your Blood Test Results: A UK Guide (2026)

Understand your blood test results in plain English. What each biomarker means, what reference ranges really tell you, and when to act.

17 min read

Full Blood Count (FBC) Explained: What It Tests, Results & Ranges (UK 2026)

Red cells, white cells, platelets, haemoglobin and MCV explained in plain English. NHS reference ranges, what abnormal results mean, common patterns, and when to act.

12 min read

Blood Tests Normal But Still Feel Ill UK: The Optimal Range Gap Explained (2026)

Your GP said your blood tests are normal but you still feel unwell? 10 biomarkers in the grey zone — ferritin, TSH, vitamin D, B12, HbA1c and more — NHS vs optimal ranges, 5 result patterns, and what to do next.

Longevity

2 guides

18 min read

The Best Blood Tests for Longevity (UK 2026)

15 science-backed biomarkers that predict biological age and healthspan — from hs-CRP and ApoB to homocysteine and DHEA-S.

16 min read

Can a Blood Test Tell Your Biological Age? (UK 2026 Guide)

How PhenoAge, GrimAge and UK Biobank algorithms estimate biological age from 9 routine blood biomarkers.

Hormones

6 guides

14 min read

Testosterone Levels by Age: What's Normal in the UK (2026)

Normal testosterone levels for men and women by age in nmol/L. BSSM clinical thresholds, the grey zone explained, free T vs total T.

16 min read

Low Testosterone Symptoms in Men: 12 Warning Signs & What to Do (UK 2026)

Fatigue, brain fog, low libido, weight gain — 12 symptoms of low testosterone explained. BSSM thresholds and evidence-based fixes.

16 min read

Testosterone Blood Test UK: What's Tested, Results Explained & Next Steps (2026)

Total testosterone, free testosterone, SHBG, LH, FSH and prolactin — what a full panel includes, NHS vs optimal ranges, 6 result patterns, evidence-based ways to raise testosterone naturally, and when to consider TRT.

17 min read

Cortisol Blood Test UK: What It Measures, Results Explained & Stress Hormone Guide (2026)

Morning cortisol, diurnal rhythm, the cortisol:DHEA-S ratio explained in plain English. NHS vs optimal ranges, overtraining, burnout, and when to see your GP.

17 min read

Hormone Imbalance Blood Test UK: What to Test, Results Explained & When to Worry (2026)

Testosterone, oestrogen, thyroid, cortisol, DHEA-S — what each marker means, NHS vs optimal ranges, symptoms of imbalance, and when to see your GP.

18 min read

Erectile Dysfunction Blood Test UK: Hormones, Cardiovascular & Metabolic Markers to Check (2026)

Beyond the blue pill — the 10 blood tests that reveal hormonal, vascular, and metabolic causes behind ED. Testosterone, SHBG, prolactin, thyroid, HbA1c, lipids, hs-CRP. NICE CG35 investigations, 5 result patterns, GP vs Helvy comparison, and 7 FAQs.

Heart Health

7 guides

20 min read

Heart Palpitations Blood Test UK: 10 Biomarkers That Reveal Treatable Causes (2026)

TSH, FT4, FT3, ferritin, FBC, magnesium, vitamin D, HbA1c, hs-CRP, potassium — the 10 biomarkers behind palpitations with a normal ECG. NICE CKS pathway, NHS vs optimal ranges, 5 result patterns, 7 FAQs.

16 min read

Heart Health Blood Test: What to Test & Why Cholesterol Alone Isn't Enough (UK 2026)

ApoB, Lp(a), hs-CRP, HbA1c and a full lipid panel — the blood tests that actually predict heart disease.

18 min read

ApoB Blood Test UK: Why It Matters More Than LDL & What Your Results Mean (2026)

Apolipoprotein B is the single best blood marker for cardiovascular risk. Learn what ApoB measures, why standard cholesterol tests miss it, and what your levels mean.

16 min read

Cholesterol Blood Test UK: What's Tested, What Results Mean & Why LDL Isn't Enough (2026)

Total cholesterol, LDL, HDL, triglycerides, ApoB and Lp(a) explained. NHS reference ranges vs optimal targets, the TC:HDL ratio, and when a standard lipid panel isn't enough.

19 min read

Blood Test for High Blood Pressure UK: Which Tests You Need & What Results Mean (2026)

8 key biomarkers for hypertension (kidney function, HbA1c, lipids, electrolytes, thyroid, hs-CRP, ApoB), NHS vs optimal cardiovascular ranges, NICE NG136 guidelines, secondary hypertension screening, and 5 blood test patterns.

19 min read

Lp(a) Blood Test UK: The Inherited Heart Risk Your GP Probably Hasn't Checked (2026)

Lipoprotein(a) is 80–90% genetic, affects 1 in 5 people, and the ESC recommends testing at least once in every adult's lifetime. What Lp(a) is, what your levels mean, and what to do if yours is elevated.

17 min read

Omega-3 Blood Test UK: Omega-3 Index, EPA, DHA & Cardiovascular Risk Explained (2026)

The omega-3 index measures EPA and DHA in red blood cell membranes. Most UK adults sit at 4–5% — well below the 8–12% optimal zone. REDUCE-IT and VITAL trial evidence, dietary sources, supplementation guidance, and 7 FAQs.

GLP-1 Medications

2 guides

15 min read

Blood Tests for Ozempic, Mounjaro & Wegovy Users (UK Guide 2026)

Which blood tests should you get before and during GLP-1 treatment? Liver, kidney, thyroid, metabolic and nutritional biomarkers explained.

18 min read

Blood Tests for Women on GLP-1 Drugs During Perimenopause (UK 2026)

Bone loss, muscle depletion, thyroid disruption, gallbladder risk — the compounded dangers of Ozempic + perimenopause.

Vitamins & Nutrition

6 guides

12 min read

Vitamin D Deficiency in the UK: Symptoms, Testing & How to Fix It

1 in 6 UK adults are vitamin D deficient. Symptoms, optimal blood levels, supplementation doses, and when to get tested.

16 min read

Iron Deficiency Blood Test UK: Ferritin, Iron Studies & What Your Results Mean (2026)

Complete guide to iron deficiency blood tests. Ferritin, serum iron, TIBC, and transferrin saturation explained — with NHS vs optimal ranges, the three stages of deficiency, and when to worry.

17 min read

Vitamin B12 Blood Test UK: What It Measures, Results Explained & Deficiency Guide (2026)

Serum B12, active B12, MMA and homocysteine explained in plain English. NHS vs optimal ranges, deficiency symptoms, the grey zone, and when to see your GP.

19 min read

Vitamin Deficiency Blood Test UK: Which Vitamins to Check & What Results Mean (2026)

Vitamin D, B12, folate, iron, magnesium, zinc, selenium and omega-3 — the 10 nutritional markers that explain fatigue, hair loss, brain fog, and poor immunity. NHS vs optimal ranges.

18 min read

Magnesium Blood Test UK: Serum, RBC & Ionised Magnesium Explained (2026)

Magnesium is involved in 600+ enzymatic reactions — from ATP energy to sleep, heart rhythm and mental health. Serum vs RBC magnesium, NHS vs optimal ranges, deficiency symptoms, who should test, and which supplement forms actually work.

16 min read

Vegan Blood Test UK: Which Nutrients to Check, Common Deficiencies & How Often to Test (2026)

The 10 blood markers every vegan should track — B12, ferritin, vitamin D, omega-3 index, zinc, iodine, folate, calcium, selenium and a full blood count. EPIC-Oxford evidence, NHS vs optimal ranges, and practical supplementation advice.

Symptoms

7 guides

22 min read

Always Tired? 12 Blood Tests That Reveal Why (UK 2026)

12 biomarkers behind persistent fatigue — ferritin, thyroid, hormones, inflammation — NHS vs optimal ranges, 5 named fatigue patterns, red flags, and evidence-based management.

19 min read

Headache & Migraine Blood Test UK: Iron, Thyroid, B12 & Inflammation Biomarkers Explained (2026)

Ferritin, TSH, vitamin B12, folate, vitamin D, magnesium, HbA1c, CRP/ESR — the 10 biomarkers that reveal treatable causes of headache and migraine. NICE CG150, NHS vs optimal ranges, 5 result patterns, 7 evidence-based interventions.

19 min read

Fibromyalgia Blood Test UK: ESR, Thyroid, Iron, Vitamin D & ANA Biomarkers Explained (2026)

ESR, hs-CRP, TSH, FT4, ferritin, FBC, vitamin D, B12, HbA1c, ANA — the 10 biomarkers that rule out treatable conditions mimicking fibromyalgia. NICE CKS, EULAR 2017, 5 result patterns, 7 evidence-based interventions.

19 min read

Joint Pain Blood Test UK: RA, Gout, Autoimmune & Inflammatory Arthritis Biomarkers Explained (2026)

hs-CRP, ESR, uric acid, rheumatoid factor, anti-CCP, ANA, vitamin D, ferritin, HbA1c — the 10 biomarkers that distinguish inflammatory arthritis, gout, haemochromatosis, and autoimmune disease from wear-and-tear joint pain.

18 min read

Hair Loss Blood Test UK: Which Markers to Check & What Results Mean (2026)

Ferritin, thyroid, testosterone, vitamin D, zinc — the blood tests that explain hair thinning, optimal ranges for hair health, when to see your GP, and evidence-based next steps.

20 min read

Chronic Fatigue Blood Test UK: ME/CFS Biomarkers, NICE NG206 Tests & What Your Results Mean (2026)

Beyond 'your bloods are normal' — the 10 blood tests that distinguish ME/CFS from treatable conditions. Thyroid, ferritin, vitamin D, cortisol, hs-CRP, HbA1c, B12, FBC, coeliac screen, and ANA. NICE NG206 investigations, 5 result patterns, 6 treatable mimics, and 7 FAQs.

16 min read

Night Sweats Blood Test UK: 10 Biomarkers That Reveal the Cause (2026)

Night sweats affect 1 in 3 adults — but the NHS rarely tests beyond basic bloods. Thyroid, hormones, HbA1c, cortisol, ferritin, vitamin D, magnesium, hs-CRP: the 10 biomarkers behind nocturnal sweating, 5 result patterns, and when to worry.

Comparison

3 guides

8 min read

Home Blood Tests vs GP Blood Tests: Which Is Better?

An honest comparison of private home blood tests and NHS GP blood tests — cost, speed, what gets tested, and when each makes sense.

9 min read

NHS vs Private Blood Tests: Which Should You Choose?

What the NHS tests, what it doesn't, and when paying for private blood work is genuinely worth it. An honest comparison for UK adults.

18 min read

Best Blood Tests UK 2026: What to Test, How to Choose & What It Costs

An evidence-based comparison of private blood tests in the UK. Test tiers, costs, turnaround times, the 10 most important biomarkers, and how to choose the right panel.

Supplements

1 guide

9 min read

Which Supplements Are Actually Worth Taking? Let Your Blood Decide

Most people waste money on supplements they don't need. Blood testing shows exactly what's low — and what's not worth the capsule.

Thyroid

1 guide

16 min read

Thyroid Blood Test UK: What It Measures, Results Explained & When to Test (2026)

TSH, Free T4, Free T3 and thyroid antibodies explained. NHS reference ranges vs optimal levels, symptoms of thyroid dysfunction, and when to get tested.

Women's Health

5 guides

18 min read

Women's Health Blood Test UK: What to Test & Why It Matters (2026)

The complete guide to blood tests for women. Hormones, thyroid, iron, vitamin D, bone health, fertility, PCOS, and perimenopause — what to test at every age.

18 min read

Menopause Blood Test UK: Which Hormones to Check, Results Explained & When to Test (2026)

FSH, oestradiol, LH, AMH, thyroid — NICE NG23 guidelines explained, NHS vs private testing, HRT monitoring, perimenopause diagnosis, and what your results actually mean.

20 min read

Perimenopause Blood Test UK: Which Tests to Ask For & What Your Results Actually Mean (2026)

Why FSH alone can’t diagnose perimenopause, the 10 biomarkers that actually help (thyroid, ferritin, AMH, vitamin D, testosterone), NHS vs optimal ranges, NICE NG23 guidelines, and when to test.

18 min read

PCOS Blood Test UK: Which Hormones to Check, Results Explained & Diagnosis Guide (2026)

Testosterone, SHBG, LH:FSH ratio, fasting insulin, DHEA-S, AMH — Rotterdam criteria, NHS diagnostic gaps, four phenotypes, and what your results actually mean.

16 min read

Postpartum Blood Test UK: 10 Biomarkers Every New Mother Should Check (2026)

Pregnancy depletes iron, vitamin D, B12, thyroid, magnesium and hormones — but the NHS 6-week check rarely tests any of them. 10 postpartum biomarkers, NHS vs optimal ranges, 5 depletion patterns, and evidence-based recovery steps.

Fertility

1 guide

19 min read

Fertility Blood Test UK: What to Test Before Trying to Conceive, Results Explained & NHS vs Private (2026)

AMH, FSH, LH, oestradiol, progesterone, thyroid, prolactin, testosterone — fertility hormone testing explained for UK couples. NHS pathway gaps, optimal timing, and how to interpret your results.

Brain Health

2 guides

17 min read

Can a Blood Test Detect Dementia? What Science Says in 2026

p-tau217, the NHS ADAPT trial, and six biomarkers you can check today that are linked to brain health. Evidence-based UK guide.

19 min read

Brain Fog Blood Test UK: 9 Biomarkers That Explain Why You Can’t Think Clearly (2026)

Thyroid, ferritin, B12, vitamin D, HbA1c, folate, hs-CRP, testosterone and iron studies — the 9 biomarkers that reveal the physical causes of brain fog. NHS vs optimal ranges for cognition, 5 result patterns, and evidence-based interventions.

Metabolic Health

5 guides

20 min read

Metabolic Health Blood Test UK: 10 Biomarkers That Reveal Whether Your Metabolism Is Working For or Against You

Only 12% of UK adults are metabolically healthy. HbA1c alone misses insulin resistance by years. This guide covers the 10 biomarkers — including fasting insulin, HOMA-IR, ApoB, and hs-CRP — that catch metabolic dysfunction before it becomes type 2 diabetes.

22 min read

Diabetes Blood Test UK: Every Test Explained, What Your Results Mean & How to Catch Risk Years Earlier

HbA1c, fasting glucose, OGTT, fasting insulin and HOMA-IR — every diabetes blood test in the UK explained. NHS thresholds vs optimal ranges, prediabetes window, type 1 vs type 2, and which extra markers catch risk years earlier.

16 min read

HbA1c Blood Test UK: What It Measures, Results Explained & Prediabetes Guide (2026)

What HbA1c measures, NHS vs optimal ranges, prediabetes explained, type 2 diabetes risk factors, and evidence-based ways to lower your levels.

17 min read

Liver Function Test UK: What LFTs Measure, What Results Mean & When to Worry (2026)

ALT, AST, ALP, GGT, bilirubin and albumin explained. NHS reference ranges vs optimal levels, NAFLD screening, the ALT:AST ratio, and when abnormal liver enzymes need investigation.

18 min read

Pre-Diabetes Blood Test UK: HbA1c, Fasting Insulin & Early Warning Signs (2026)

5.1 million people in England have pre-diabetes. HbA1c, fasting glucose, fasting insulin, HOMA-IR, triglycerides and vitamin D — the 6 markers that catch insulin resistance early. NHS thresholds vs optimal, the DPP 58% evidence, and what to do next.

Kidney & Organ Health

1 guide

17 min read

Kidney Function Test UK: What It Measures, Results Explained & When to Worry (2026)

Creatinine, eGFR, urea, electrolytes and ACR explained. NHS reference ranges vs optimal levels, CKD staging, the diabetes–hypertension connection, and when abnormal kidney markers need investigation.

Inflammation

3 guides

17 min read

Inflammation Blood Test UK: CRP, hs-CRP & ESR Explained (2026)

hs-CRP vs CRP vs ESR, cardiovascular risk stratification, chronic low-grade inflammation, NHS vs optimal ranges, and evidence-based ways to lower inflammatory markers.

18 min read

Immune System Blood Test UK: WBC, Immunoglobulins & Lymphocytes Explained (2026)

White blood cell differential, immunoglobulins, lymphocyte subsets, neutrophil-to-lymphocyte ratio, vitamin D and zinc — the blood markers that reveal how well your immune system is actually working. NHS vs optimal ranges, 5 result patterns, and evidence-based interventions.

18 min read

Autoimmune Blood Test UK: 10 Key Markers, Patterns & When to Test (2026)

hs-CRP, ESR, FBC, thyroid, ferritin, B12, vitamin D, liver function, kidney function, and HbA1c — the screening markers that flag autoimmune conditions before antibody testing. 5 result patterns, 8 common conditions, NICE referral criteria, and 7 FAQs.

Weight Management

2 guides

18 min read

Weight Loss Blood Test UK: What to Check Before, During & After Losing Weight (2026)

Thyroid, insulin resistance, cortisol, vitamins and hormones — the 12 biomarkers that explain why weight loss stalls and how to break through. With GP comparison table.

14 min read

Unexplained Weight Gain Blood Test UK: 10 Biomarkers Your GP Might Miss (2026)

Complete UK guide to blood tests for unexplained weight gain. Thyroid, insulin resistance, cortisol, testosterone, oestrogen, SHBG, vitamin D, inflammation — NHS vs optimal ranges, 5 result patterns, evidence-based next steps.

Blood Health

1 guide

18 min read

Anaemia Blood Test UK: Types, Results Explained & What to Do Next (2026)

FBC, ferritin, B12, folate and iron studies explained. Three types of anaemia classified by MCV, NHS reference ranges vs optimal, five result patterns, and when to see your GP.

Sleep & Recovery

1 guide

18 min read

Sleep Blood Test UK: 8 Biomarkers That Affect Your Sleep (2026)

Ferritin, thyroid TSH, vitamin D, magnesium, cortisol, testosterone, B12 and iron — the 8 biomarkers linked to insomnia, night waking and poor sleep quality. NHS ranges vs optimal, 5 result patterns, and evidence-based interventions.

Sports & Fitness

1 guide

18 min read

Athlete Blood Test UK: What to Test, Results Explained & Sports Performance Guide (2026)

The 12 biomarkers every athlete should track — ferritin, testosterone, cortisol, vitamin D, thyroid, CRP and more. NHS vs athletic optimal ranges, overtraining patterns, RED-S, and periodised testing.

Mental Health

1 guide

19 min read

Blood Test for Anxiety & Depression UK: 10 Biomarkers Your GP Should Check (2026)

Thyroid, iron, vitamin D, B12, cortisol, blood sugar, inflammation and magnesium — the blood tests that rule out physical causes before assuming it's 'just stress'. NICE guidelines, NHS vs private comparison, and 7 FAQs.

Men's Health

2 guides

14 min read

PSA Blood Test UK: Prostate Testing Explained, Levels by Age & What Raised Results Mean (2026)

Age-specific PSA thresholds, free PSA ratio, PSA velocity, ethnic risk factors, the MRI-first pathway after a raised result, and how to get tested — NHS vs private. 7 FAQs, NICE NG131/NG12, PROMIS & PRECISION trial evidence.

15 min read

TRT Blood Tests UK: What to Monitor Before, During & After Testosterone Replacement (2026)

Complete UK guide to blood tests for TRT monitoring. Haematocrit, PSA, oestradiol, lipids, liver function — BSSM 2022 guidelines, NHS vs private gaps, 5 result patterns, red-flag thresholds.

Digestive Health

4 guides

16 min read

Gut Health Blood Test UK: What Your Blood Reveals About Digestion, Inflammation & Nutrient Absorption (2026)

CRP, coeliac screen, iron studies, B12, folate, liver function, FBC, vitamin D and thyroid — 11 blood markers that reveal gut problems. NHS vs private comparison, when you need stool tests, and 7 FAQs.

16 min read

Bloating Blood Test UK: 10 Biomarkers That Reveal What’s Behind Persistent Bloating (2026)

Persistent bloating affects up to 30% of adults — yet the NHS typically tests just 2 of the 10 relevant markers. Coeliac screen, thyroid, ferritin, B12, folate, vitamin D, hs-CRP, liver function, FBC: what each reveals, 5 result patterns, and evidence-based next steps.

18 min read

IBS Blood Test UK: Which Tests Rule Out Something Serious & What to Keep Monitoring (2026)

IBS affects 10–20% of UK adults — but it’s a diagnosis of exclusion. 10 biomarkers for IBS investigation (tTG-IgA, hs-CRP, FBC, ferritin, TSH, FT4, vitamin D, B12, folate, HbA1c), NICE NG61 pathway, 5 result patterns, IBS vs IBD differentiation, and evidence-based next steps.

18 min read

Coeliac Blood Test UK: The Full Serological Pathway — Why a Single tTG Isn’t Enough (2026)

1 in 100 UK adults have coeliac disease — 64% undiagnosed, 13-year average delay. Full NICE NG20 pathway (tTG-IgA + total IgA + EMA + IgG alternatives), the IgA deficiency trap, 6 downstream deficiency markers, 5 result patterns, gluten challenge rules, and evidence-based next steps.

Preventive Health

2 guides

16 min read

Blood Tests for Over 40s: What to Check and Why It Matters (UK 2026)

Why your 40s are a turning point for health and which biomarkers matter most. NHS Health Check vs private panel comparison, cardiovascular, metabolic, hormonal and nutritional markers explained, testing frequency, and 7 FAQs.

16 min read

Health MOT Blood Test UK: What to Check, What It Costs & How to Get One (2026)

What a proper health MOT should include beyond the NHS Health Check — 8 body systems, 50+ biomarkers, cost comparison from £39 to Harley Street, age-specific testing guides, and how to do it from home.

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