Blood Tests: GP Reviewed Information
Blood tests are commonly used in primary care to investigate symptoms, monitor long term conditions and provide reassurance about general health. This section of the AccessGP Knowledge Base explains key blood tests often discussed during private GP consultations, what they measure and how results are usually interpreted in context.
What this blood tests section covers
This section includes GP reviewed summaries of routine blood tests used in everyday clinical practice. These articles describe what each marker looks for and how it may contribute to a wider health assessment. The topics include:
- full blood count
- kidney function
- liver function
- bone profile
- lipid profile including ApoB and Lp(a)
- HbA1c
- thyroid tests (TSH and free T4)
- creatine kinase
- vitamin D
- PSA
- testosterone
- iron, ferritin, B12 and folate
- ESR or Erythrocyte Sedimentation Rate
- Anti-CCP (autoimmune)
- tTG-IgA (coeliac screening)
Each article provides clear, non diagnostic information based on current clinical understanding.
Common reasons adults have blood tests
People may be advised to have blood tests when experiencing symptoms such as fatigue, low energy, weight change, palpitations, digestive symptoms or joint pains. Blood tests also support:
- general health screening
- cardiovascular risk assessment (lipids, ApoB, Lp(a))
- hormone and men’s health reviews (testosterone, PSA)
- thyroid symptoms
- vitamin or iron deficiency concerns
- diabetes screening (HbA1c)
- monitoring liver or kidney function when taking long term medicines
- assessing muscle symptoms (creatine kinase)
- investigation of digestive symptoms (tTG-IgA)
- autoimmune symptom patterns (Anti-CCP)
- A private GP selects tests based on your symptoms, medical history and clinical need.
In private GP care, blood tests are selected after a clinical discussion to ensure they are relevant and help guide next steps.
Types of blood tests explained in this section
Below is an overview of the main test categories covered. Each has a dedicated article for more detail.
Full blood count (FBC)
An FBC measures red cells, white cells and platelets. It can help identify anaemia, inflammation or infection patterns.
Kidney and renal function test (U+Es)
Kidney function tests usually include urea, creatinine and estimated glomerular filtration rate (eGFR). They help assess how well the kidneys are working and are often checked when monitoring blood pressure medicines and other long term treatments.
Liver function tests (LFTs)
LFTs look at enzymes and bilirubin levels that help assess liver irritation, bile flow and the impact of medicines.
Bone Profile
Assesses calcium, phosphate and related markers. Used in bone health assessments and certain metabolic conditions.
HbA1c and blood sugar tests
HbA1c reflects blood sugar levels over several months and is used to screen for and monitor diabetes.
Lipid profile (cholesterol, ApoB and Lp(a))
A standard lipid panel measures total cholesterol, HDL, LDL and triglycerides.
Advanced markers such as Apolipoprotein B (ApoB) and Lipoprotein(a) [Lp(a)] provide additional information about cardiovascular risk and are used more frequently in private GP health checks.
ApoB – reflects the number of cholesterol particles contributing to plaque development
Lp(a) – a genetically determined particle linked to increased long-term cardiovascular risk
These markers are interpreted alongside family history, blood pressure and lifestyle factors.
Thyroid function tests
TSH and and T4, help assess whether the thyroid gland is underactive or overactive.
Creatine Kinase (CK)
A muscle enzyme that may rise with muscle injury, strenuous exercise or certain medications. Useful for muscle symptoms.
Vitamin D
Assesses levels relevant to fatigue, bone health, immune function and general wellbeing.
PSA (Prostate Specific Antigen)
Used in prostate health assessments and men’s health reviews. Interpreted carefully alongside age, symptoms and risk factors.
Testosterone
Assessed when exploring symptoms such as low energy, reduced libido or hormone concerns. Always interpreted alongside lifestyle and wider health markers.
Iron, Ferritin, B12 and Folate
These nutrients help assess anaemia, fatigue and low mood. Common in general health checks.
Inflammation marker (Erythrocyte Sedimentation Rate, ESR)
ESR may help indicate inflammation or infection when interpreted with other clinical findings.
Anti-CCP
A specialist antibody used in the assessment of autoimmune joint symptoms.
tTG-IgA (Coeliac Screening)
A sensitive test used to screen for coeliac disease in digestive or nutrient-related symptoms.
How a GP uses blood tests in practice
Blood tests are interpreted alongside symptoms, medical history, medication review and any relevant examinations or scans. Results can guide lifestyle advice, follow-up testing or further assessment when necessary. Normal results may provide reassurance even when symptoms are present, while abnormal results often require careful interpretation and may need repeat testing.
Linking blood tests to wider health checks
Blood tests often form part of broader assessments, including heart health reviews, hormone checks, fatigue investigations and digestive symptom assessments. Individual test pages in this section link to related topics across the Knowledge Base.
When to book a GP appointment about blood tests
Consider a GP consultation if:
- you are unsure which tests are appropriate
- you have symptoms that are persistent or unclear
- you received results you do not fully understand
- you want a tailored private health check
- you need follow up of abnormal or borderline results
A private GP can review your concerns and help plan next steps.
If you would like to discuss blood tests, review existing results or plan a private health check, you can book an online GP appointment with AccessGP.
Last reviewed by Dr Zamiel Hussain, GMC registered GP
Updated: 7 December 2025