Blood test results explained: how to read your report

Blood test results can be difficult to interpret, particularly when you're looking at a report full of numbers, ranges and green, amber or red flags. What does each result actually mean? And why might a Bluecrest result look different from one you received from your GP?

The answer often comes down to reference ranges. Different laboratories and healthcare settings can use different ranges when interpreting the same health marker. Understanding how these ranges work can make your results easier to read and put them into context.

What do blood test results mean?

A blood test measures different markers in your blood. Depending on the test, these might include cholesterol, blood sugar, iron stores, vitamin levels, hormones, liver function or kidney function.

Your result is usually compared with a reference range. This gives you an indication of how your result compares with values considered typical or clinically relevant for the group and testing method being used.

A result outside a reference range does not automatically mean you have a health problem. Equally, a result within a reference range does not necessarily mean there is nothing worth keeping an eye on. Your results need to be considered alongside your symptoms, medical history and other health information.

What is a blood test reference range?

A reference range is a set of values used to help interpret a test result. There isn't one universal reference range for every blood test.

Ranges can vary between laboratories because they may use different testing equipment, methods and reagents. The population and evidence used to establish the range can also differ.

This means that the same numerical result can sometimes appear differently on two reports. That doesn't necessarily mean that one test is wrong.

Reference ranges are also designed for different purposes. In a clinical setting, a range may help identify results that could indicate a health problem requiring further investigation or treatment. Preventative health assessments may use additional evidence to identify results that could be worth monitoring or improving before they become a clinical concern.

Why do my Bluecrest results look different from my GP's?

If you've compared a Bluecrest blood test with a result from your GP and noticed that the reference ranges aren't the same, this can understandably be confusing.

The difference may be due to the laboratory, testing method or reference range being used. It can also reflect the purpose of the test.

GP blood tests are carried out in a clinical setting, where the aim is to investigate symptoms, diagnose conditions or monitor existing health problems. Bluecrest Health Assessments take a preventative approach, looking at a wider range of health markers and identifying areas that may be worth keeping an eye on.

This means you could have a result within your GP's clinical reference range but be flagged amber on a Bluecrest report.

That doesn't mean your GP's assessment was wrong or that you have a medical problem. It means the two results are being interpreted against different criteria.

What do green, amber and red blood test results mean?

Bluecrest uses a colour-coded system to make your results easier to understand.

• Green generally means your result is within the expected range.
• Amber indicates a result that may be worth paying attention to or monitoring. An amber result does not necessarily mean you have a medical condition or need treatment. It can simply highlight an opportunity to consider your lifestyle, monitor a result over time or discuss it with a healthcare professional.
• Red indicates a result that falls outside the range used by Bluecrest and may require further medical attention. If you receive a red result, you should contact your GP and share the result with them so they can advise you on what to do next.

The colour of a result is only one part of the picture. Your results should always be considered in context rather than viewed in isolation.

If you're unsure how to interpret your report, you can read our guide to understanding your private health assessment results.

Why might a blood test result be amber if it's 'normal' at my GP?

This is one of the most common reasons people can find blood test reports confusing.

A result can be within a clinical reference range used by your GP while still being flagged amber by a preventative health assessment.

For example, some health markers have a broad range of values seen across the general population. Being within that range does not necessarily mean there is no value in monitoring the result or considering whether lifestyle changes could improve it.

Bluecrest's preventative approach uses clinical guidance, laboratory reference data and research evidence to help identify results that may be worth paying attention to.

The important point is that an amber result isn't a diagnosis. It is information that may give you something to monitor or discuss.

If you're unsure about an amber result, you can speak to your GP or another healthcare professional who can consider it alongside your wider health and medical history.

What can blood test results tell you?

The information provided by a blood test depends on which markers have been tested. Some common examples include:

Vitamin D

Vitamin D is important for maintaining healthy bones and muscles. Blood testing can show whether your vitamin D level is within the range being assessed.

A low vitamin D result may prompt you to discuss your diet, lifestyle or supplementation with a healthcare professional.

Ferritin and iron stores

Ferritin is a marker of the amount of iron stored in your body. Low iron stores can occur before iron deficiency anaemia develops and may be associated with symptoms such as tiredness.

If your ferritin result is low, your GP can help determine whether further investigation or changes to your diet or treatment are appropriate.

Cholesterol

Cholesterol is a type of fat found in your blood. Your cholesterol levels are one of several factors that can contribute to your risk of cardiovascular disease.

Looking at cholesterol alongside other information, such as blood pressure, age and lifestyle factors, can provide a more useful picture than looking at the cholesterol number alone.

Blood pressure

Blood pressure isn't a blood test, but it is commonly included alongside blood testing as part of a wider health assessment.

High blood pressure often has no obvious symptoms, which is why checking it can be useful even when you feel well.

Blood sugar

Blood tests such as HbA1c can provide information about your average blood sugar levels over the previous few months. This can help identify whether your blood sugar is within the expected range or whether further assessment may be appropriate.

What should you do if your blood test result is abnormal?

Don't panic if one of your results is outside the expected range. There are many reasons why a result can vary, and one abnormal result does not necessarily mean that you have a health condition.

Your GP can help interpret results in the context of your symptoms, medical history and other tests. They may recommend repeating a test, carrying out further investigations or simply monitoring the result.

If you've had a Bluecrest Health Assessment and are concerned about a result, share your report with your GP where appropriate. They can help you understand whether anything needs further investigation or follow-up.

Why looking at your results over time can be useful

A single blood test gives you information about your health at a particular point in time. Looking at results over time can sometimes provide additional context.

For example, you may notice that a particular marker is gradually changing, even though each individual result remains within its reference range. Tracking results can help you identify patterns and give you useful information to discuss with your GP or healthcare professional.

This is one of the benefits of taking a preventative approach to your health. The information it provides can help you understand your health and decide what, if anything, you want to focus on.

Take a closer look at your health with Bluecrest Wellness

If you'd like a broader picture of your health, a Bluecrest Health MOT brings together a range of blood tests and physical checks in one assessment. Depending on the package you choose, these can include cholesterol, blood sugar, kidney and liver function, hormone levels and other important health markers.

Your results are presented in a clear, colour-coded report with straightforward explanations, helping you understand your results and identify areas you may want to keep an eye on.

Need help? Call free on 0800 652 2183 to speak to one of our team or book a Bluecrest Health MOT today.

This article is for general health information purposes and does not constitute medical advice. If you have questions or concerns about your blood test results, speak to a healthcare professional.