A comprehensive health check through blood testing is one of the most effective ways to gain a complete picture of your overall health. Rather than waiting for symptoms to appear, a full blood test panel can detect potential problems early, identify nutritional deficiencies, and provide valuable insights into how your major organs are functioning.

But what exactly is included in a comprehensive blood test? This guide breaks down the key components of a full health screen, explaining what each test measures and why it matters for your wellbeing.

What Is a Comprehensive Blood Test?

A comprehensive blood test, sometimes called a full health screen or wellness panel, is a collection of individual blood tests that together provide an extensive overview of your health. Unlike a single test that looks at one specific marker, a comprehensive panel examines multiple body systems simultaneously.

The exact tests included can vary depending on the provider and package chosen, but a thorough health check typically covers blood cells, organ function, metabolic health, nutritional status, and key risk factors for common diseases.

Full Blood Count (FBC)

The full blood count is a cornerstone of any comprehensive health check. It provides detailed information about the three main types of cells in your blood:

Red blood cells (RBCs):

Haemoglobin — The protein that carries oxygen

Haematocrit — The proportion of blood made up of red cells

MCV, MCH, MCHC — Measures of red cell size and haemoglobin content

White blood cells (WBCs):

Total white cell count

Differential count (neutrophils, lymphocytes, monocytes, eosinophils, basophils)

Platelets:

Platelet count — Important for blood clotting

What it reveals: Anaemia, infections, blood disorders, immune function, and clotting ability.

Liver Function Tests (LFTs)

Your liver performs over 500 vital functions, making its health crucial to your overall wellbeing. A comprehensive panel includes several markers of liver function:

ALT (Alanine aminotransferase) — Most specific marker of liver cell damage

AST (Aspartate aminotransferase) — Indicates liver or muscle damage

ALP (Alkaline phosphatase) — Related to bile duct function

GGT (Gamma-glutamyl transferase) — Sensitive to alcohol and liver stress

Bilirubin — A waste product processed by the liver

Albumin — A protein made by the liver

What it reveals: Fatty liver disease, alcohol-related damage, hepatitis, bile duct problems, and overall liver synthetic function.

For detailed information on interpreting these results, read our guide to decoding your liver function tests.

Kidney Function Tests

Your kidneys filter waste from your blood, regulate fluid balance, and help control blood pressure. Key markers include:

Creatinine — A waste product filtered by the kidneys

Urea — Another waste product indicating kidney function

eGFR (Estimated Glomerular Filtration Rate) — Calculates how well your kidneys are filtering

Electrolytes — Sodium, potassium, chloride, and bicarbonate

What it reveals: Chronic kidney disease, dehydration, electrolyte imbalances, and kidney damage from conditions like diabetes or high blood pressure.

Lipid Profile (Cholesterol Panel)

Cardiovascular disease remains a leading cause of death in the UK. A lipid profile assesses your risk by measuring:

Total cholesterol — Overall cholesterol level

LDL cholesterol — "Bad" cholesterol that contributes to arterial plaque

HDL cholesterol — "Good" cholesterol that helps remove LDL

Triglycerides — A type of fat linked to heart disease risk

Total cholesterol/HDL ratio — A useful risk indicator

What it reveals: Cardiovascular risk, familial hypercholesterolaemia, and metabolic health.

Diabetes Markers

With diabetes affecting millions in the UK, screening is an essential part of any comprehensive health check:

Fasting glucose — Blood sugar level after fasting

HbA1c (Glycated haemoglobin) — Average blood sugar over 2-3 months

What it reveals: Diabetes, prediabetes, and blood sugar control. For more details, read our comprehensive guide to understanding the A1C blood test.

Thyroid Function Tests

The thyroid gland regulates metabolism, energy, and numerous body functions. A comprehensive panel typically includes:

TSH (Thyroid-stimulating hormone) — The primary screening marker

Free T4 — The main thyroid hormone

Free T3 — The active thyroid hormone (in more comprehensive panels)

What it reveals: Hypothyroidism (underactive thyroid), hyperthyroidism (overactive thyroid), and thyroid disease. Learn more about the thyroid's effects on your body in our article on whether low thyroid can cause headaches.

Iron Studies

Iron is essential for oxygen transport and energy production. A complete iron panel includes:

Serum iron — Iron circulating in your blood

Ferritin — Your iron stores

Transferrin/TIBC — Iron transport capacity

Transferrin saturation — Percentage of transferrin carrying iron

What it reveals: Iron deficiency anaemia, iron overload (haemochromatosis), and chronic disease.

Vitamin and Mineral Levels

Nutritional deficiencies are common and can significantly impact how you feel. Key vitamins and minerals often included are:

Vitamin D — Essential for bones, immunity, and mood

Vitamin B12 — Crucial for nerve function and red blood cell production

Folate — Important for cell division and particularly vital during pregnancy

What it reveals: Deficiencies that can cause fatigue, weakness, neurological symptoms, and bone problems.

Inflammatory Markers

Chronic inflammation is linked to numerous health conditions. Key markers include:

CRP (C-Reactive Protein) — General inflammation marker

ESR (Erythrocyte Sedimentation Rate) — Another inflammation indicator

What it reveals: Infection, autoimmune conditions, and chronic inflammatory diseases. For more information, read our overview of the C-reactive protein test and learn how the ESR blood test assesses inflammation.

Additional Tests in Extended Panels

More comprehensive health screens may also include:

Uric acid — Related to gout and kidney stones

Calcium and bone profile — For bone health assessment

Prostate-specific antigen (PSA) — For men, to screen for prostate issues

Hormone panels — Including testosterone, oestrogen, or cortisol

Insulin — To assess insulin resistance

Who Should Get a Comprehensive Health Check?

While everyone can benefit from periodic health screening, comprehensive blood tests are particularly valuable for:

Adults over 40 seeking baseline health information

Those with family history of diabetes, heart disease, or other conditions

People experiencing unexplained symptoms like fatigue or weight changes

Anyone wanting to optimise their health proactively

Those who have not had blood tests in several years

For guidance on important tests to consider, read our article on the top 10 important blood tests.

What to Expect During Your Health Check

A comprehensive blood test is straightforward:

1. Preparation — Most panels require fasting for 8-12 hours

2. Blood draw — A small sample is taken from your arm

3. Analysis — Your sample is processed in an accredited laboratory

4. Results — Typically available within 24-72 hours

5. Review — Results are explained clearly, with guidance on any abnormal findings

For more details on the testing process, read our guide on the procedure, results, and after-effects of blood testing.

Comprehensive Health Screening in London

At [Private Blood Tests London](/), we offer a range of comprehensive health check packages at our CQC-registered clinic in South Kensington. From essential screens to advanced wellness panels, our experienced healthcare team helps you choose the right tests for your needs.

We provide professional, efficient service with results delivered quickly and securely. Our team takes the time to explain your results clearly, ensuring you understand what they mean for your health.

Explore our [health screening packages](/health-screening), view our [blood test prices](/blood-test-prices), and see our [full range of tests](/all-blood-tests).

Invest in your health with a comprehensive blood test — book your appointment today.

Comprehensive Health Checks: What's Included in a Full Blood Test?