What Can a Blood Test Tell You About Your Health?

A blood test may be recommended for several reasons. It can form part of a general health check, help investigate symptoms or assess your risk of developing certain health conditions.

Blood tests may also be used to monitor an existing condition, check how well a treatment is working or assess how medication is affecting your body.

Blood tests can measure a wide range of health markers, depending on the type of test requested. These may include:

• Red and white blood cells
• Blood sugar levels
• Cholesterol and other blood fats
• Liver and kidney function
• Thyroid function
• Iron, vitamin B12 and vitamin D levels
• Hormone levels
• Markers of inflammation

No single blood test checks for every health condition. The markers included will depend on the selected test or package, your symptoms and any concerns you wish to investigate. A healthcare professional can help you choose the most appropriate option.

A healthcare professional may recommend a blood test if you have symptoms such as persistent tiredness, unexplained weight changes, frequent infections, dizziness, unusual bruising or changes in your appetite.

Blood tests may also help investigate whether symptoms could be linked to hormone imbalances, vitamin deficiencies or changes in liver, kidney or thyroid function.

Your results should be considered alongside your symptoms, medical history and any further clinical assessment that may be required.

Not all blood tests require fasting. For some tests, you may be asked not to eat or drink anything other than water for a specified period beforehand. Other tests may require different preparation, depending on the health markers being measured.

At your appointment, a healthcare professional will usually take a small blood sample from a vein on the inside of your elbow. A soft band may be placed around your upper arm to make the vein easier to access. The sample is collected into one or more small tubes and sent to a laboratory for analysis.

The procedure usually takes only a few minutes. You may feel a brief scratch or slight discomfort when the needle is inserted. Afterwards, cotton wool or a small plaster will be placed over the area.

Your results will show the levels of the health markers included in your chosen test or package. These are usually compared with reference ranges, although a result outside the expected range does not always mean that you have a health condition.

A healthcare professional should consider your results alongside factors such as your symptoms, medical history, current medication and previous test results. Depending on the findings, you may be advised that no further action is needed or that follow-up testing, treatment or a specialist assessment should be considered.

Harley Street Medical offers a wide range of private blood tests, from individual health markers to comprehensive testing packages covering different areas of health and wellbeing.

If you are unsure which test to book, our clinical team can discuss your symptoms, concerns and health history to help you identify a suitable option. The markers included, preparation requirements and expected result times vary between tests, so please review the information for your chosen service before booking.