Blood tests are among the most valuable tools in modern medicine. A simple blood sample can reveal crucial information about your health, from detecting early signs of disease to monitoring how well your organs are functioning. Whether you are proactively managing your wellness or investigating specific symptoms, knowing which blood tests matter most can help you take control of your health.
Here are the top 10 most important blood tests that everyone should consider as part of their health monitoring routine.
1. Full Blood Count (FBC)
The full blood count, also known as a complete blood count, is one of the most commonly performed blood tests and provides a comprehensive overview of your blood cells. It measures:
Why it matters: An FBC can detect anaemia, infections, blood disorders, and even some cancers. It is often the first test ordered when investigating fatigue, weakness, or unexplained symptoms.
2. Liver Function Tests (LFTs)
Your liver performs over 500 essential functions, including filtering toxins, producing proteins, and storing energy. Liver function tests measure enzymes and proteins that indicate how well your liver is working.
Key markers include:
Why it matters: Elevated liver enzymes can indicate liver damage from alcohol, medications, fatty liver disease, or viral hepatitis. Early detection allows for lifestyle changes before serious damage occurs. Learn more in our detailed guide to decoding your liver function tests.
3. Kidney Function Tests
Your kidneys filter waste products from your blood, regulate fluid balance, and help control blood pressure. Kidney function tests assess how effectively your kidneys are performing these vital tasks.
Key markers include:
Why it matters: Kidney disease often has no symptoms in its early stages. Regular testing can detect problems before they become serious, particularly important for those with diabetes, high blood pressure, or a family history of kidney disease.
4. Lipid Profile (Cholesterol Test)
A lipid profile measures the fats in your blood and is essential for assessing cardiovascular risk. High cholesterol is a major risk factor for heart attacks and strokes.
What it measures:
Why it matters: Cardiovascular disease remains the leading cause of death in the UK. A lipid profile helps identify your risk and guides decisions about diet, lifestyle, and medication. Adults should have their cholesterol checked every 4-6 years, or more frequently if they have risk factors.
5. HbA1c (Glycated Haemoglobin)
The HbA1c test measures your average blood sugar levels over the past 2-3 months, making it invaluable for both diagnosing and monitoring diabetes.
Result interpretation:
Why it matters: Type 2 diabetes often develops silently over years. The HbA1c test can detect prediabetes, giving you the opportunity to make lifestyle changes that may prevent diabetes altogether. For a comprehensive understanding, read our guide to everything you need to know about the A1C blood test.
6. Thyroid Function Tests
Your thyroid gland controls your metabolism, energy levels, and many other bodily functions. Thyroid disorders are common, particularly in women, and can significantly impact quality of life.
Key markers:
Why it matters: An underactive thyroid (hypothyroidism) can cause fatigue, weight gain, and depression, while an overactive thyroid (hyperthyroidism) can cause anxiety, weight loss, and heart palpitations. Both conditions are treatable once diagnosed.
7. Vitamin D
Vitamin D is essential for bone health, immune function, and mood regulation. Deficiency is extremely common in the UK due to limited sunlight exposure, particularly during winter months.
Why it matters: Low vitamin D levels are associated with fatigue, muscle weakness, bone pain, and increased susceptibility to infections. Severe deficiency can lead to osteoporosis and rickets. Testing is especially important for those who spend limited time outdoors, have darker skin, or are over 65.
8. Iron Studies
Iron is essential for producing haemoglobin and transporting oxygen throughout your body. Iron studies provide a complete picture of your iron status.
What it measures:
Why it matters: Iron deficiency is the most common nutritional deficiency worldwide and a leading cause of anaemia. Symptoms include fatigue, weakness, pale skin, and shortness of breath. Conversely, iron overload (haemochromatosis) can damage organs if left untreated.
9. Vitamin B12 and Folate
Vitamin B12 and folate are essential for nerve function, red blood cell production, and DNA synthesis. Deficiency can cause serious health problems if left untreated.
Why it matters: B12 deficiency can cause fatigue, neurological problems, and a type of anaemia called megaloblastic anaemia. It is particularly common in vegans and vegetarians, older adults, and those with digestive conditions affecting nutrient absorption.
10. C-Reactive Protein (CRP)
CRP is a marker of inflammation in the body. While some inflammation is normal, chronic elevated CRP is associated with increased risk of various health conditions.
Types of CRP tests:
Why it matters: Elevated CRP can indicate infection, autoimmune conditions, or chronic disease. The hs-CRP test is increasingly used to assess cardiovascular risk, as chronic low-grade inflammation contributes to atherosclerosis. For more details, read our overview of the C-reactive protein test.
Bonus: ESR (Erythrocyte Sedimentation Rate)
Like CRP, the ESR test measures inflammation in the body. It is often used alongside CRP to help diagnose and monitor inflammatory conditions such as rheumatoid arthritis, temporal arteritis, and infections. Learn more about how the ESR blood test assesses inflammation and overall health.
When Should You Get Tested?
The frequency of blood testing depends on your age, health status, and risk factors:
Comprehensive Blood Testing in London
At [Private Blood Tests London](/), we offer all of these essential blood tests and many more at our CQC-registered clinic in South Kensington. Our experienced healthcare team provides professional, efficient service with results delivered quickly and securely to you.
Whether you want a single test or a comprehensive health screen, we can help you understand your body and take proactive steps toward better health.
Explore our [health screening packages](/health-screening), [all available tests](/all-blood-tests), and [test prices](/blood-test-prices).
Do not wait for symptoms to appear – book your blood tests today and invest in your long-term wellbeing.