Comprehensive Blood Panel
A deeper blood test panel that looks at nutrient status, thyroid markers, inflammation, blood sugar balance and other functional markers that aren’t usually included in standard NHS testing. Helpful when symptoms persist despite “normal” results.
Key blood markers included in this panel
Depending on the laboratory, a comprehensive blood panel may include:
Full blood count - overall picture of red and white blood cells
Iron studies - including ferritin, transferrin saturation and TIBC
Vitamin markers - such as B12, folate, vitamin D
Thyroid markers - often TSH, T4, T3 and thyroid antibodies
Blood sugar regulation - fasting glucose, HbA1c and sometimes insulin
Liver and kidney function markers
Inflammation markers - such as CRP
Lipid profile - cholesterol, HDL, LDL and triglycerides
Electrolytes and minerals - sodium, potassium, magnesium and calcium
Unlike a single NHS blood test request, which is usually focused on one or two areas of concern, this panel looks at multiple interconnected systems together, helping to build a clearer picture of what might be contributing to how you feel.
How the blood draw and lab process works
A comprehensive blood panel requires a venous blood sample, which is taken by a trained phlebotomist. Some markers (such as fasting glucose or lipids) may require you to fast for 8 to 12 hours beforehand, so you will be given clear instructions in advance. Results are typically available within a few days and are reviewed alongside your symptoms, health history and goals.
Who may benefit from a broader blood screen
A comprehensive blood panel may be helpful if you are experiencing:
Persistent fatigue or low energy that does not improve with rest or sleep.
Brain fog, poor concentration or low motivation.
Mood changes, low mood or feeling easily overwhelmed.
Hair thinning, brittle nails or skin changes.
Feeling cold, struggling to regulate temperature or other signs that may relate to thyroid function.
Weight changes that do not match your diet or activity levels.
Heavy or irregular periods.
Blood sugar crashes, shakiness or energy dips after eating.
Ongoing inflammation, joint pain or muscle aches.
A history of restrictive eating, low nutrient intake or digestive issues that may affect absorption.
It can also be useful when you have already had GP tests but still feel unwell, or when the testing you received was limited to only one or two markers (for example, just TSH for thyroid, or just ferritin for iron).
Why this panel often goes beyond standard GP bloods
GPs are responsible for assessing symptoms that may indicate medical conditions, and NHS testing is designed around that role. It focuses on markers that identify disease states or require medical intervention. A functional blood panel offers different, complementary insights for several reasons:
GPs test markers that have clear medical relevance for your presenting symptoms. NHS resources are carefully allocated, so GPs must limit testing to markers that are known to change medical treatment. This means many useful supportive markers (such as active B12, vitamin D, full thyroid panels or fasting insulin) may not be included unless there is a strong clinical reason.
NHS reference ranges are wide and designed to capture the general population. If your results fall within the reference range, they may be marked as normal even when they are drifting towards one end of the spectrum. Functional testing looks at patterns, ratios and shifts that can help explain symptoms even when nothing is medically abnormal.
Testing multiple systems at once is not routinely funded in general practice. A panel combining thyroid, nutrients, inflammation, blood sugar and lipids is not usually available on the NHS. This does not mean your GP has missed something. It reflects that NHS testing is not designed for personalised preventative insight.
NHS spending must remain focused on diagnosis and treatment. Many markers in a functional blood panel can guide nutrition and lifestyle support, but they do not typically alter prescribed treatment. As a result, they are not included in standard NHS pathways.
This makes a comprehensive blood panel complementary to GP care, not a replacement. It adds context and detail that can be helpful for tailoring nutrition and lifestyle strategies, particularly when symptoms are persistent but not severe enough to meet the threshold for medical intervention.
What a comprehensive blood picture can show
A comprehensive blood panel does not diagnose medical conditions, but it can highlight:
Lower-end nutrient levels that may be affecting energy, mood, hair or skin.
Iron patterns (for example, low ferritin despite normal haemoglobin) that help explain fatigue or heavy periods.
Thyroid trends that relate to symptoms, even if TSH is within the normal range (for example, low free T3, or positive thyroid antibodies).
Inflammation markers that may reflect immune activation or system stress.
Blood sugar regulation patterns that may contribute to energy dips, cravings or mood swings.
Lipid patterns linked with metabolic health, cardiovascular risk or hormone production.
Liver and kidney markers that provide overall context about how well these systems are functioning.
The value lies in the overall picture, not individual numbers. Functional interpretation looks at how different systems interact, which can reveal patterns that would be missed if each marker were assessed separately.
Using blood markers to shape nutrition and lifestyle changes
When a comprehensive blood panel is reviewed, the results are always considered alongside your symptoms, health history, medications, GP tests, diet, stress, sleep and lifestyle. Depending on the findings, the focus may include:
Nutrients to prioritise through food (for example, iron-rich foods, oily fish for omega-3, egg yolks and liver for vitamin A, nuts and seeds for magnesium).
Eating patterns that support stable energy and blood sugar, such as balanced meals with adequate protein, healthy fats and fibre.
Thyroid-friendly nutrition and lifestyle factors, including adequate iodine (from dairy, fish or seaweed), selenium (from Brazil nuts), avoiding excessive raw goitre-promoting vegetables, and managing stress and sleep.
Ways to reduce inflammation through diet, such as a Mediterranean-style pattern rich in vegetables, olive oil, oily fish, nuts, seeds and polyphenols.
Blood sugar balancing strategies, including meal timing, protein distribution and reducing refined carbohydrates.
Whether any supplements would be appropriate (for example, vitamin D if deficient, or iron if ferritin is low), and where they are unnecessary.
The aim is always practical guidance that fits into your real life, not overwhelming protocols or unnecessary supplementation.
Blood results and symptoms that should always be shared with your GP
If your blood results suggest anything that should be investigated medically (for example, very low haemoglobin, significantly elevated liver enzymes, very high or very low thyroid hormones, or concerning lipid patterns), you will be guided to share them with your GP so that appropriate tests, referrals or treatment can be arranged.
Book your free call
You don’t need to decide on a test before seeking support. If you’re experiencing ongoing symptoms and are wondering whether a more detailed blood panel could offer clarity, we can explore your concerns and history together first. From there, we can decide whether testing is likely to be useful, or whether it makes more sense to begin with foundational nutrition and lifestyle steps.
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