Blood Tests Explained: What They Can (and Can't) Tell You About Your Health | Canterbury

Blood tests are one of the most common medical investigations carried out in the UK. They can help identify deficiencies, monitor long-term health conditions, investigate symptoms, and provide useful information about certain aspects of your health. But with so many different tests available, it can be difficult to know where to start.

Whether you've been advised to have a blood test by a healthcare professional or you're simply curious about what testing may be available, here's what you need to know.

Why are blood tests used?

Blood tests are used for a wide range of reasons. They can help healthcare professionals:

• Investigate symptoms

• Diagnose some health conditions

• Monitor existing medical conditions

• Check how well certain medications are working

• Identify vitamin or mineral deficiencies

• Assess aspects of general health and wellbeing

Different blood tests look for different things, so the most appropriate test depends on the person's symptoms, medical history and reason for testing.

Can a blood test tell you everything about your health?

No. Blood tests can provide valuable information, but they are only one piece of the picture.

A blood test result often needs to be considered alongside:

• Symptoms

• Medical history

• Physical examination findings

• Lifestyle factors

• Other investigations

For this reason, healthcare professionals rarely make decisions based solely on a blood test result.

What types of blood tests are available?

There are hundreds of different blood tests available. Some of the more commonly requested tests include:

Full Blood Count (FBC)

This looks at different types of blood cells and can help identify issues such as certain types of anaemia, infection or other blood-related conditions.

Cholesterol and Lipid Testing

These tests measure different types of cholesterol and fats in the blood and can help assess cardiovascular risk.

HbA1c (Diabetes Screening)

HbA1c measures average blood sugar levels over the previous two to three months and is commonly used to screen for and monitor diabetes.

Thyroid Function Tests

These tests assess how well the thyroid gland is working and may be used when investigating symptoms such as fatigue, weight changes or changes in mood.

Vitamin D Testing

Vitamin D plays an important role in bone health, muscle function and the immune system. Low levels are relatively common in the UK.

Vitamin B12 Testing

Low vitamin B12 levels can contribute to symptoms such as tiredness, weakness and neurological symptoms.

Liver Function Tests

These assess various markers associated with liver health and function.

Should you have a blood test if you're feeling tired?

Tiredness is one of the most common reasons people enquire about blood testing. However, there isn't usually a single "fatigue blood test".

Many possible causes of tiredness can be explored through blood testing, including:

• Iron deficiency

• Vitamin B12 deficiency

• Vitamin D deficiency

• Diabetes

• Thyroid disorders

However, fatigue can also have many non-medical causes, including stress, sleep problems, caring responsibilities and lifestyle factors.

This is why it's often important to consider symptoms in context rather than simply selecting a test at random.

Why are some blood tests only available through certain providers?

A question we're often asked is:

"Can I have any blood test I want?"

The answer is... not always.

Some blood tests are straightforward screening or monitoring tests. Others require specialist interpretation, follow-up advice or medical support if an abnormal result is identified.

For this reason, some testing is arranged through specialist providers who have clinicians available to review and explain the results.

How does private blood testing work?

There are several routes available depending on the type of testing you need.

Blood tests arranged directly through our clinic

We offer a range of commonly requested blood tests that can be arranged directly through our Canterbury clinic.

Specialist health testing providers

We are also partner clinics for providers such as Medichecks, Goodbody and Better2Know.

In these cases, patients purchase their testing package directly through the provider and we carry out the blood draw appointment locally. The provider then manages the results process and any associated clinical review.

Blood draws requested by another healthcare professional

If another healthcare professional has requested a blood test and will be responsible for reviewing and explaining the results, we may be able to carry out the blood draw on their behalf.

Are private blood tests worth it?

The answer depends on your circumstances.

For some people, private blood testing offers convenience, quicker access or the ability to investigate a specific health concern.

However, a useful blood test starts with the right question.

The most comprehensive testing package is not necessarily the most helpful one. In many cases, targeted testing is more useful than carrying out a large number of investigations without a clear reason.

Things to consider before booking a blood test

Before arranging testing, it can be useful to think about:

• Why you want the test

• Whether you're experiencing any symptoms

• Whether you know which test is appropriate

• Who will explain the results

• What you would do if an abnormal result is identified

Understanding these points can help ensure you choose the most appropriate pathway.

Blood Testing in Canterbury

If you're considering blood testing and aren't sure where to start, we're happy to discuss the options available.

We offer a range of blood tests directly through our Canterbury clinic and can also carry out blood draws for a number of specialist testing providers.

You can view our current blood testing options on our Blood Tests page.

If you're arranging testing through Medichecks, Goodbody, Better2Know or another provider, contact us to discuss blood draw appointments.

Frequently Asked Questions

Do I need to fast before a blood test?

Some blood tests require fasting, while others do not. The requirements depend on the specific test being performed. If fasting is required, you'll usually be asked not to eat or drink anything other than water for a set period before your appointment. We'll let you know in advance if fasting is needed for your specific test, so there's no need to guess.

How long does it take to get blood test results?

This depends on the test being carried out and the laboratory processing it.

As a general guide, most results are reported by the laboratory within 3–5 working days of the sample being received. We aim to pass results on as soon as we receive them, often on the same day, although occasional delays can occur due to postal services or laboratory processing times. Some specialist tests may take longer.

Can I book a blood test without seeing a GP?

Yes, in many cases.

We offer a range of blood tests directly through our clinic, and we can also carry out blood draws for several specialist testing providers, including Medichecks, Goodbody and Better2Know.

If another healthcare professional has requested testing and will be responsible for reviewing and explaining the results, we may also be able to carry out the blood draw on their behalf.

How do I know which blood test I need?

Many people know they have a concern they'd like to investigate but aren't sure which test is most appropriate.

In many cases, it's better to seek advice first rather than choosing a test at random. The most expensive or comprehensive test isn't always the most useful. Understanding what you're trying to investigate can help you select the right test and avoid paying for tests that aren't relevant.

Can blood tests detect every health condition?

No. Blood tests can provide valuable information about many aspects of health, but they cannot diagnose every condition and they do not replace a clinical assessment. Results often need to be considered alongside symptoms, medical history and, in some cases, further investigations.

Blood tests are usually most useful when they're used to answer a specific clinical question rather than as a standalone health check.

What happens if my results are abnormal?

That depends on how the blood test was arranged.

For tests purchased through providers such as Medichecks, Goodbody or Better2Know, the provider will usually review the results and explain any findings.

For blood tests requested by another healthcare professional, that clinician would normally be responsible for reviewing the results and discussing any follow-up actions with you.

If you're arranging testing directly through our clinic, we'll explain in advance how results will be reported and what support is available.

Can you take blood for Medichecks, Goodbody or Better2Know tests?

Yes. If you've purchased a blood testing package from Medichecks, Goodbody or Better2Know that requires a venous blood sample, we can usually carry out the blood draw appointment locally at our Canterbury clinic.

The testing provider remains responsible for analysing the sample, reporting the results and providing any associated clinical interpretation.