Blood tests can identify a range of issues in your body that will help your doctor diagnose any conditions you may (or may not) have. They are a key diagnostic, observation and maintenance tool for people living with blood cancer.
Preparing for a blood test
Depending on the kind of blood test you are having, you may need to prepare for the test. This may mean fasting (not eating) for 8 or 12 hours prior to the test, not eating certain foods that may affect the results, or not taking certain kinds of medications. You may also be asked to not smoke or consume alcohol before the test.
It is highly recommended you drink 8 to 10 glasses of water on the days leading up to your test as being hydrated helps with blood flow. Being hydrated also helps veins stick out and be found more easily for the procedure.
Having a blood test
If your doctor has requested you have a blood test, depending on your situation, you can have blood drawn at your GP’s clinic, at a pathology collection service or while you are in hospital. Depending on where you go, either a doctor, nurse or phlebotomist will be performing the procedure.
Typically, blood will be withdrawn from inside your elbow as your veins are most visible here.
Depending on the kind of tests your doctor has requested, the person withdrawing your blood will require any number of vials of your blood, but don’t be worried, in each vial there is usually only about 2 or 3 millilitres – not enough to be harmful to you.
Though you may feel a slight discomfort when the needle is inserted, and you may have a small bruise afterwards, blood tests are considered harmless.
Some people experience dizziness or nausea after having blood taken, so make sure to let your collector know if you feel unwell so they can take steps to make you feel more comfortable.
Once you have had your blood withdrawn, it is then labelled and sent to the lab for testing.
One good resource is Lab Tests Online-Australasia which has a comprehensive list of different types of blood tests along with detailed explanations of what each are for.
The Full Blood Count (FBC) test
A Full Blood Count Test, commonly known as an FBC test (also known as a CBC), is one of the most common types of blood tests doctors request. This test measures various types of cells in your blood and is often used to monitor whether those levels are rising or falling.
There are many reasons why someone would need a FBC test – whether the doctor is screening you for various cancers, monitoring your health during treatment, or monitoring your recovery. As conditions such as blood cancers don’t have clear external signs (such as rashes, legions or discolouring) that indicate your health, your doctor may ask for regular FBC tests to monitor your progress, no matter what stage of an illness you are at.
An FBC test measures a number of different variables in your blood:
White blood cell count
Also known as a leukocyte count, a white cell count measures the number of white blood cells found per litre of blood.
White blood cell differential
Looks at the types of white blood cells present in the sample and classifies them according to cell type. It may also identify any immature (blast) cells.
Red blood cell count
Also called an erythrocyte count, measures the number of red blood cells found per litre of blood.
The proportion of your blood that is made of red blood cells, measured as a ratio.
The amount of protein in red blood cells that carries oxygen.
Measures the number of platelets in your blood. Mean Platelet Volume (MPV) measures the average size of your platelets.
The following figures are considered normal for adults, but children, elderly people or people with an illness will have different levels of normal. Keep in mind that any results should be reviewed by a doctor or qualified medical professional.
|Test||Normal range results|
|Red blood cell count||Male: 4.35-5.65 trillion cells/L
(4.32-5.72 million cells/mcL)
|Female:3.92-5.13 trillion cells/L
(3.90-5.03 million cells/mcL)
|White blood cell count||3.4-9.6 billion cells/L
(3,400 to 9,600 cells/mcL)
|Platelet count||Male:135-317 billion/L
(135,000 to 317,000/mcL)
|Female: 157-371 billion/L
For more information on the FBC, go to Lab Tests Online.
Developed by the Leukaemia Foundation in consultation with people living with a blood cancer, Leukaemia Foundation support staff, haematology nursing staff and/or Australian clinical haematologists. This content is provided for information purposes only and we urge you to always seek advice from a registered health care professional for diagnosis, treatment and answers to your medical questions, including the suitability of a particular therapy, service, product or treatment in your circumstances. The Leukaemia Foundation shall not bear any liability for any person relying on the materials contained on this website.