Updated by Dr Francesca Haarer BSc, PG Cert (Med Ed), BMBS, MRCS and Dr Kate Smith BSc, MBChB 

Updated date May 2025

Whether your goal is feeling better in general or focused on something specific, a simple blood test could tell you a lot about your overall physical health – not to mention giving you a sneak peek into how well your body’s working.

From vitamin deficiencies to hormone function, let’s take a closer look at what your blood could tell you about your health.

Check your general health

Blood testing can be an important tool in keeping track of your overall physical health.

Doctors and other trained healthcare professionals can use your blood sample to search for markers of disease, investigate possible reasons for new symptoms, and monitor the current condition of your overall health.

See how well your organs are working

Many blood tests, including our general wellness blood test, check how well some of your vital organs are working.

The types of potential issues that can show up in a blood test include problems with your thyroid, liver and kidneys.

Evaluate your hormone levels

Doctors can use a blood sample to check your hormone levels and detect possible hormone imbalances.

Hormones like testosterone, oestrogen, progesterone and thyroid-stimulating hormone (TSH) are visible in specific blood tests.

Measuring thyroid hormone levels can help detect autoimmune conditions like hypothyroidism, and measuring other hormones can be useful for a range of reasons including as part of fertility testing.¹,²

Discover vitamin deficiencies

If you are concerned you’re not getting enough essential vitamins from your diet or have symptoms of vitamin deficiency, a blood test can check if you’re low in certain vitamins and may indicate how well your diet is supporting your overall health.

By checking critical nutrients like iron, vitamin D, and vitamin B12, your test results can indicate whether or not your body is getting what it needs from your food or environment. For example, if you are vegan you may be at increased risk of being low in certain vitamins including B12.³

If you are found to be low in certain vitamins you can then plan to get more of these through a healthy, balanced diet or through dietary supplements if appropriate.⁴,⁵ For vitamin D, our main source is from sunlight, so the NHS advises we all consider a supplement throughout the autumn and winter.⁶

Check your supplements are working

If you already know you’re low in a specific vitamin or mineral , you may have already altered your diet or been taking supplements to boost your intake.

Your blood test can indicate whether your dietary changes or supplement regime is working by measuring whether your vitamin levels are within the normal range.  

Uncover underlying conditions

Many health problems have symptoms associated with them, but you might not be aware of what they are. Other health issues may be symptomless, particularly in the early stages. Blood tests can search for markers that may indicate any underlying conditions.

For example, suppose your blood test shows your liver or kidney function is abnormal, but you might not always have any symptoms.⁷,⁸ This may prompt your doctor to ask you a few more questions or order further investigation.

Another symptomless condition on its own is high cholesterol – but a blood test can help identify it so it can be managed.⁹ By measuring the different types of fat in your bloodstream, doctors can understand your cholesterol levels and make an estimate of whether you’re at higher risk of heart disease.¹⁰

This understanding can help you make lifestyle changes to lower your cholesterol, or the NHS advises that some people may be advised by their doctor to start medication.¹¹

The final word

Different blood tests can tell you a lot about your health and wellbeing when interpreted by a doctor.

From detecting specific health conditions to examining your general health, markers in your blood can be useful signals to help you understand more about your body.

Take H&B&Me’s general wellness blood test to uncover detailed insights in a report from one of our doctors. You never know – you might discover ways to improve your health that you’d never even considered. Good luck!

References:

1. NHS . Underactive thyroid (hypothyroidism) [Internet]. NHS. 2021. Available from: https://www.nhs.uk/conditions/underactive-thyroid-hypothyroidism/

2. CKS is only available in the UK [Internet]. NICE. Available from: https://cks.nice.org.uk/topics/infertility/management/management/

3. NHS. The vegan diet [Internet]. nhs.uk. 2022. Available from: https://www.nhs.uk/live-well/eat-well/how-to-eat-a-balanced-diet/the-vegan-diet/

4. NHS. Iron Deficiency Anaemia [Internet]. NHS. 2024. Available from: https://www.nhs.uk/conditions/iron-deficiency-anaemia/

5. NHS . Vitamin B12 or folate deficiency anaemia [Internet]. NHS. 2023. Available from: https://www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/

6. NHS. Vitamin D - Vitamins and Minerals [Internet]. NHS. 2020. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-d/

7. Guidance for the management of abnormal liver blood tests [Internet]. Available from: https://elearning.rcgp.org.uk/pluginfile.php/175104/mod_book/chapter/587/page%201%20LFT%20management.pdf 

8. NHS. Diagnosis - chronic kidney disease [Internet]. NHS. 2019. Available from: https://www.nhs.uk/conditions/kidney-disease/diagnosis/ 

9. NHS . What Is High cholesterol? - High Cholesterol [Internet]. NHS. 2022. Available from: https://www.nhs.uk/conditions/high-cholesterol/ 

10. NHS. High cholesterol - Getting tested [Internet]. nhs.uk. 2019. Available from: https://www.nhs.uk/conditions/high-cholesterol/getting-tested/ 

11. NHS Choices. Medicines for high cholesterol - High cholesterol [Internet]. NHS. 2020. Available from: https://www.nhs.uk/conditions/high-cholesterol/medicines-for-high-cholesterol/