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How to read a blood test

How to read a blood test

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Having a blood test done may be something you’ve had as a one-off, or it may be part of your regular health routine to check if your body is functioning as it should be. Once the quick and simple procedure if over, you’ll be sent your blood test results. 

Blood tests are carried out to investigate how your body is working, how well it’s functioning and how well it is balancing different chemicals, proteins, pressures and more. Your blood test can also show any abnormalities that may lead to medical diagnosis too. Did you know that many cancer diagnoses are determined from blood test results?

Having a blood test isn’t anything to be scared of – and for your doctor or nurse it’s a normal part of their everyday routine – our team of experienced GPs will walk through the steps of what happens and help put you at ease if you’re feeling nervous.

Remember! You shouldn’t eat for 8 hours before a blood test, because it can alter the results you see.

When your blood sample has been taken, it’ll be sent off to a specialist lab, where a pathologist will examine the sample to look for anything abnormal or noteworthy. When your results come back to you, your doctor should discuss everything in detail, and let you know what everything means.

However, it’s always useful and important to understand what is on our blood test results and what the numbers mean – it means you can refer to the test in the future without needing to go back to the doctors.

Here’s our guide to what you’ll find on your blood test and how to make sense of what it means.

Basic Metabolic Panel

The most common blood test that you’ll receive at the doctors, will be your Basic Metabolic Panel. A Basic Metabolic Panel is a series of different tests that help doctors gather information about your body and assess how key functions in your body are currently performing.

This includes how well your liver and kidneys are working, your blood sugar levels, how high your cholesterol is, your calcium levels, and your protein and electrolyte levels. Your doctor will interpret these results to form a diagnosis.

This blood test may be able to give your doctor an idea as to whether your body may be struggling with:

  • blood filtration
  • electrolyte levels
  • irregular PH balance in your blood
  • blood sugar levels
  • kidney problems
  • lung problems
  • problems with your pancreas
  • issues with insulin / metabolism


Here are some of the key terms or data you may find within your blood test, and a key as to what they mean:

  • Albumin: 3.9 to 5.0 g/dL – this indicates the measure of protein within your blood
  • Alkaline phosphatase: 44 to 147 IU/L – this indicates the status of your liver and nutrition
  • ALT (alanine aminotransferase): 8 to 37 IU/L – this indicates how well your liver is functioning
  • AST (aspartate aminotransferase): 10 to 34 IU/L – this indicates the kidney and liver status
  • BUN (blood urea nitrogen): 7 to 20 mg/dL – this indicates how well the kidney and heart are functioning
  • Calcium: 8.5 to 10.9 mg/dL – Calcium is a key indicator to bodily health – as it’s crucial to many bodily functions. This measures the amount of calcium in your blood
  • Chloride: 96 – 106 mmol/L – Can indicate blood poisoning and alkalosis/acidosis. It also looks at the PH balance in your body
  • CO2 (carbon dioxide): 20 to 29 mmol/L – This gives a measurement of metabolic function and looks at the pH balance of your blood. A view on how well your kidney is functioning
  • Glucose test: 100 mg/dL – Indicator of diabetes and measures the function of insulin in your body
  • Potassium: 3.7 to 5.2 mEq/L – Measure potassium levels in your bloodSodium: 136 to 144 mEq/L – Measures hydration status, can be an indicator towards many diseases
  • Total bilirubin: 0.2 to 1.9 mg/dL – Indicator of liver function
  • Total protein: 6.3 to 7.9 g/dL – A measure of infection and liver or kidney diseases


Cholesterol Panel

You may also get your cholesterol panel taken during a blood test, and this will mean a separate set of results to go through. A cholesterol panel is a test that measures the amount of fat in your blood, and the different varieties of fats too. Doctors will use this test to check that you have a good ratio between good fats and bad fats.

Here are some terms and works you may find in the results from your cholesterol panel:

  • LDL cholesterol: <100 mg/dL is optimal – your “bad” cholesterol HDL cholesterol: >40-59 mg/dL (>60 considered protective against heart disease) – your “good” cholesterol
  • Total cholesterol: <200mg/dL – The measure of your combined LDL & HDL
  • Triglyceride: <150 mg/dL – measures the different kinds of fat in the blood


Blood pressure

Another key number you’ll find on your blood work, is your blood pressure. Blood pressure shows us how hard our heart is working to pump blood around the body. Blood pressure is written as systolic/diastolic pressure. Note: higher number equals more “pressure” on the heart.

  • Optimal—120/80 or lower
  • Prehypertension—120-139/80-89
  • High—140/90 or greater


People with high blood pressure, will be advised to introduce more exercise into their daily routines, to build up the strength of their heart. High blood pressure can put you at a higher risk of heart disease and stroke.

If you ever have any additional questions about your blood test result, it’s always a good idea to chat to your doctor directly. Remember, our doctors will always be happy to clarify your results and any other related questions.

Read more about our blood test services and how we can help you: