Blood Tests

A blood test is a scientific analysis of your blood. 

What are blood tests?
Why do I need blood tests?
What are the risks of having a blood test?
How do I prepare for a blood test?
What happens during a blood test?
What happens after a blood test?

What are blood tests?

A blood test is when a sample of your blood is taken via a needle and sent to a lab for testing.

Blood tests help diagnose diseases and monitor treatments. They can also measure some substances in your blood, including medication levels.

Why do I need blood tests?

You may have a blood test if your doctor needs more information to help find out why you may be having unusual symptoms. A blood test will help make a diagnosis. 

A blood test can help your doctor to see: 

  • How well you lungs are working
  • How well your organs are working (eg liver and kidneys)
  • How well your treatment is working
  • If you have an infection
  • Whether you are at risk for certain lung disease
  • Whether you are at risk of a blood clot.

You can read about some common blood tests for lung health below:

Name

What it looks at

Used to help diagnose

Full Blood Count (FBC)

Red blood cells, white blood cells, platelets

Anaemia, infection, blood clotting

Urea and electrolytes

Levels of sodium, potassium, urea, creatinine

Problems with your kidneys

Hydration status

Cystic Fibrosis Tests

CF gene mutation, sweat chloride, pancreatic elastase, immunoreactive trypsin

Cystic fibrosis

Alpha-1 antitrypsin

AAT deficiency

Lung (COPD) and liver disease

Blood Cultures

Bacteria, fungus

Lung infections that have entered the blood system

 

           

 

 

What are the risks of having a blood test?

There are few, if any, risks or side effects of having a blood test. Some people feel a mild sting when the needle goes in. You may develop a small bruise.

How do I prepare for a blood test?

In many cases, you don’t need to do anything before your blood test.

Some blood tests require you to stop eating (fast) 8 hours before the test. If you need to fast before your blood test, your doctor will tell you. 

What happens during a blood test?

During your blood test:

  • You will meet with a doctor, nurse, or blood collector (phlebotomist) in a private room
  • The health professional will sterilize a small patch on your arm
  • A needle will be inserted into a vein in your arm
  • A small amount of blood will be taken and packaged
  • The needle will be removed.

You’ll need to apply gentle pressure with a cotton ball and tape where the needle was inserted (to prevent bruising or bleeding).

What happens after a blood test?

Your health professional will send your blood sample to a lab for testing. The results will be sent to your doctor (this usually takes a few days).

Your doctor will contact you to discuss the results of your blood test and book a follow-up appointment if necessary.