Blood tests are one of the most common medical tests.
Blood tests are used to:
- check your general health
- check if you have an infection
- check how well certain organs are working - such as your liver and kidneys
- screen for certain genetic conditions
You also have blood tests if you are pregnant.
A blood sample is needed for your blood tests.
This is usually taken by a:
- doctor or GP
- nurse
- phlebotomist (a specialist in taking blood samples)
Book a blood test
Contact your GP to book a blood test.
Your GP may:
- do your blood test
- refer you to a hospital
If you have a medical card, routine blood tests should be free.
But you may have to pay for a blood test if your GP thinks:
- your blood test is not routine
- a blood test is not needed for your condition
Ask your GP if you are not sure if you have to pay for your blood test.
If you have a medical card and you paid for a blood test, contact your Local Health Office. They will give you advice.
Preparing for a blood test
Your GP or nurse will tell you if you need to do anything before your test.
You may need to:
- avoid eating or drinking (except for water) for up to 12 hours before your appointment
- stop taking a certain medicine
But this depends on the type of blood test you have.
Important
Follow the instructions your GP or nurse gives you.
If you do not, this may:
- affect your results
- delay your test
- mean you need to repeat your test
What happens during a blood test
Most blood tests only take a few minutes.
Your GP, nurse or phlebotomist will:
- Place a tight band (tourniquet) around your upper arm - this makes it easier for them to take your blood.
- Clean the skin around your vein.
- Put a needle into a vein inside your elbow or the back of your hand - you may feel a pinch when the needle goes in.
- Take your blood sample.
- Remove the needle and put cotton wool on the area where the needle went in.
Blood tests for children
Blood samples from children are often taken from the back of their hand.
Your child's skin may be numbed with a special spray or cream before the sample is taken.
If you are worried about needles
Tell the person who is taking your blood if you:
- are nervous about needles and blood
- feel dizzy and faint during or after your blood test
- have felt dizzy or fainted during or after a blood test before
They can try to make you feel more comfortable. For example, by letting you lie down for the test.
After the test
Only a small amount of your blood is taken during a blood test. You should not feel any serious effects after your test.
You may have a small bruise where the needle went in. This will fade after a few days.
Blood test results
Ask your GP or nurse:
- when you will get your results
- how you will get your results
- if they will talk to you about your results
- if they will tell you what happens next
Contact your GP if you have not received your results or you do not understand them.
If you are worried about your test results
If you are worried about the results of your test, take a friend or family member that you trust with you.
For some tests, such as HIV or genetic testing, you will be offered specialist counselling to help you cope with your results.
Content supplied by the NHS and adapted for Ireland by the HSE
