Top 10 Blood Tests Every Man and Woman Should Know About
"A blood test can reveal far more than most people realise. From your heart and thyroid to your hormones, kidneys and vitamin levels, modern blood testing provides valuable insights into your health, often before symptoms develop."Tharb Faisl
Whether you're feeling perfectly well or investigating symptoms such as fatigue, weight changes or hormonal imbalance, blood tests are one of the most powerful tools available in modern medicine.
The challenge isn't finding a blood test, it's knowing which ones are actually useful.
With hundreds of laboratory investigations available, it can be difficult to know where to start.
In this guide, we'll explore 10 of the most important blood tests that doctors commonly use to assess overall health, explain what each test measures and when it may be recommended.
At Marylebone Diagnostic Centre (MDC), our doctor-led team offers comprehensive private blood testing from our clinic at 73 Baker Street, Marylebone, London W1U 6RD, helping patients make informed decisions about their health through evidence-based diagnostics.
Explore all of our diagnostic services: https://www.marylebonediagnosticcentre.com/services/
Why Blood Tests Matter
Blood circulates through every organ in the body.
As a result, laboratory analysis can provide valuable information about:
- Heart health
- Liver function
- Kidney function
- Hormones
- Nutrition
- Inflammation
- Immune function
- Diabetes
- Infection
- Fertility
- Metabolic health
Rather than waiting until symptoms become severe, blood tests often help identify changes at an earlier stage when further investigation or treatment may be more effective.
The Top 10 Blood Tests
1. Full Blood Count (FBC)
One of the most commonly requested investigations, the Full Blood Count (FBC) measures the different types of cells circulating in your blood.
It helps doctors investigate:
- Anaemia
- Infection
- Inflammation
- Blood disorders
- General health
If you're experiencing fatigue, recurrent infections or unexplained bruising, an FBC is often one of the first tests recommended.
2. Kidney Function Tests
Your kidneys continuously filter waste products from your bloodstream.
Kidney function blood tests help assess how well they are working and may identify early signs of kidney disease before symptoms develop.
These tests are also commonly used to monitor conditions such as high blood pressure and diabetes.
3. Liver Function Tests
The liver performs hundreds of essential functions, including processing nutrients, producing proteins and helping remove waste products from the body.
Liver function tests help assess liver health and may be recommended if you experience symptoms such as fatigue, abdominal discomfort or abnormal skin or eye colour.
4. Cholesterol Profile
Heart disease remains one of the leading causes of illness in the UK.
A cholesterol profile measures different types of cholesterol and blood fats to help assess cardiovascular risk.
Combined with blood pressure, diabetes screening and lifestyle assessment, it provides valuable information about long-term heart health.
5. Diabetes Screening (HbA1c and Glucose)
Type 2 diabetes often develops gradually without obvious symptoms.
Blood tests such as HbA1c and glucose measurements help identify elevated blood sugar levels and may detect diabetes or pre-diabetes before complications develop.
6. Thyroid Function Tests
Your thyroid influences metabolism, energy levels, body temperature, mood and fertility.
A comprehensive Thyroid Profile may include tests such as:
- TSH
- Free T4
- Free T3
- Thyroid antibodies where clinically appropriate
Thyroid testing may be recommended if you experience:
- Fatigue
- Hair loss
- Weight changes
- Feeling unusually cold or hot
- Anxiety
- Irregular menstrual cycles
Learn more about our Thyroid Profiles: https://www.marylebonediagnosticcentre.com/thyroid-profiles/
7. Iron Studies and Ferritin
Iron plays a vital role in producing healthy red blood cells.
Iron deficiency remains one of the most common nutritional deficiencies worldwide and may contribute to:
- Fatigue
- Shortness of breath
- Hair thinning
- Poor concentration
- Reduced exercise tolerance
Ferritin helps assess the body's iron stores and is often measured alongside other iron studies.
8. Vitamin B12 and Vitamin D
Vitamin deficiencies can affect multiple body systems.
Testing Vitamin B12 and Vitamin D may be appropriate for people experiencing:
- Low energy
- Muscle weakness
- Numbness or tingling
- Bone discomfort
- Frequent illness
Rather than taking supplements without knowing your levels, testing helps guide evidence-based treatment.
Where appropriate, patients with confirmed deficiencies may also benefit from our Medical Injectable Therapies.
https://www.marylebonediagnosticcentre.com/intramuscular-im-injections/
9. Hormone Blood Tests
Hormones regulate many essential body functions.
Depending on your symptoms, hormone testing may help investigate:
For women:
- Menopause
- Irregular periods
- Fertility
- Polycystic Ovary Syndrome (PCOS)
Women's Health: https://www.marylebonediagnosticcentre.com/men-women-health/women-health/
For men:
- Low testosterone
- Reduced libido
- Erectile dysfunction
- Fatigue
- Fertility concerns
Male Fertility: https://www.marylebonediagnosticcentre.com/services/male-fertility-testing-in-central-london/
10. Inflammatory Markers
Inflammatory markers help doctors assess whether inflammation may be present somewhere in the body.
Although these tests do not diagnose a specific disease on their own, they may contribute to investigating infections, autoimmune conditions and inflammatory disorders when interpreted alongside other clinical information.
Which Blood Tests Do You Actually Need?
This is perhaps the most important question.
The answer is not everyone needs all 10.
The most appropriate investigations depend on:
- Your age.
- Sex.
- Symptoms.
- Family history.
- Existing medical conditions.
- Lifestyle.
- Current medication.
At Marylebone Diagnostic Centre, we believe blood testing should be personalised rather than based on a standard checklist.
Our doctors recommend investigations that are appropriate for your individual circumstances.
| Symptom | Blood tests commonly considered |
|---|---|
| Fatigue | FBC, Ferritin, Iron Studies, Vitamin B12, Vitamin D, Thyroid Function, HbA1c |
| Hair loss | Ferritin, Iron Studies, Thyroid Profile, Vitamin D, Vitamin B12 |
| Weight gain | Thyroid Profile, HbA1c, Lipid Profile |
| Weight loss | Thyroid Profile, HbA1c, FBC |
| Low libido | Testosterone (men), hormone profile, thyroid function |
| Frequent infections | FBC, Vitamin D, inflammatory markers |
| Irregular periods | Female hormone profile, thyroid function, iron studies |
Beyond Blood Tests
Sometimes blood tests form only one part of a wider diagnostic assessment.
Depending on your symptoms, your doctor may also recommend:
Urine Testing
To investigate urinary symptoms or kidney health.
Sexual Health Screening
Confidential blood and laboratory testing for sexually transmitted infections.
Allergy Testing
To investigate persistent allergic symptoms.
https://www.marylebonediagnosticcentre.com/marylebone-allergy-profiles/
Cancer Screening
Appropriate screening based on age, symptoms and family history.
https://www.marylebonediagnosticcentre.com/cancer-screening/
Why Choose Marylebone Diagnostic Centre?
Located in the heart of Marylebone, just minutes from Baker Street Underground Station, Marylebone Diagnostic Centre provides doctor-led diagnostic services for patients across:
- Marylebone
- Westminster
- Mayfair
- Fitzrovia
- Paddington
- Regent's Park
- St John's Wood
- Greater London
Patients choose MDC because we combine:
- Comprehensive blood testing
- Experienced clinicians
- Modern laboratory diagnostics
- Personalised health assessments
- Fast appointments
- Evidence-based medicine
We don't believe in ordering every available test, we believe in recommending the right test, for the right patient, at the right time.
73 Baker Street
London W1U 6RD
Central London, near Baker Street Station
Frequently Asked Questions
What is the most important blood test to have?
There isn't a single blood test that is the most important for everyone. The right investigations depend on your age, symptoms, medical history and health goals. A Full Blood Count, kidney function, liver function, cholesterol and diabetes screening are among the most commonly recommended tests for general health assessment.
Should men and women have different blood tests?
Many core blood tests are the same, including kidney function, liver function, cholesterol and diabetes screening. However, hormone testing, fertility investigations and some health assessments may differ depending on sex, age and individual circumstances.
How often should I have blood tests?
The frequency depends on your age, existing medical conditions, family history and overall health. Some people benefit from annual wellness blood tests, while others may only require testing when symptoms develop or to monitor ongoing treatment.
Can blood tests detect all diseases?
No. Blood tests are valuable diagnostic tools but cannot diagnose every medical condition. They are most effective when interpreted alongside your symptoms, medical history, physical examination and, where appropriate, other investigations such as imaging or urine testing.
Can I request specific blood tests?
Yes. Many private blood tests can be requested directly. However, discussing your symptoms with a healthcare professional can help ensure you choose the most appropriate investigations and avoid unnecessary testing.
Ready to Book Your Blood Test?
Our doctor-led team can help you choose the right tests based on your symptoms and health goals.
