Preparing for the blood test

To help your child be as comfortable and relaxed as possible, talk to them about what will happen during the test and why it is needed.

Getting a blood sample

Blood samples are usually taken from the veins on the back of the hand or the inside of the elbow. A doctor, nurse or another specially trained healthcare professional will carry out the test.

  • A band is tightly wrapped above where blood will be taken. This allows the vein to swell with blood.
  • The skin is cleaned with an antiseptic wipe.
  • A thin needle is inserted through the skin and into a blood vessel.
  • A small amount of blood is drawn up into a syringe or special container.
  • The needle is removed.
  • A cotton wool pad is often used to stop bleeding and prevent bruising. You or your child may be asked to hold it in place. Sometimes a plaster is put over the site.

Occasionally, there is some swelling, bruising or pain around the site where the blood was taken.

Getting a small blood sample

When only a small sample of blood is needed, some hospitals will get it from the capillaries, very tiny blood vessels under the skin. This is usually on the finger, thumb or heel.

  • The skin is cleaned with an antiseptic wipe.
  • A small needle is used to pierce the fleshy part of the finger, thumb or heel.
  • The needle is removed straight away.
  • The finger, thumb or heel is squeezed and the blood collected in a small container.
  • A cotton wool pad is usually used to stop bleeding and prevent bruising. You or your child may be asked to hold this in place. Sometimes a plaster is applied.

Dealing with pain

For most children, taking blood is quick, does not hurt much and is very safe. Your child may feel a sharp scratch from the needle. A local anaesthetic spray or cream can be put on the skin before the test, to help stop your child feeling any pain.

Play specialist

A play specialist may be able to meet with your child. They will use dolls and other toys to help your child prepare for the blood test and to support and distract them during the test itself.

Other tips to help

  • You can stay with your child during the blood test. Ask the person taking the blood whether there is anything you can do to make your child more comfortable.
  • Some children like to count to five before the needle goes in or tell a story or sing a rhyme during the test.
  • Find out whether your child would like to watch the blood being taken, or whether they prefer to look away.
  • Staying calm and confident while distracting your child will help.

Complications and risks

When it is difficult to take blood

For most children, taking blood is quick, does not hurt much and is very safe.

Some children have small veins that are difficult to find and take blood from. The person taking your child’s blood will work with you and your child to find the best place to take blood.

Occasionally, they will bring a second healthcare professional to help. Sometimes they will need to take blood more than once to make sure they have enough blood for the tests or need more than one attempt to find a vein that they can take blood from.

Swelling, bruising and pain

Occasionally after a blood test, the site has swelling, bruising or pain.

Put ice on the site. Cover the ice in a bag or a cloth – do not put ice directly on the skin.

What happens to the blood?

The container with your child’s blood is labelled with their name and sent to a laboratory. Hospital staff may look at the blood under a microscope or test it with chemicals.

Your doctor or nurse will tell you when and how you get the results.

More information

  • Tests and diagnosis

    Find out more detail about some of the tests used to diagnose or investigate kidney conditions.

  • Meet a Nursery Nurse

    Debbie works as a Nursery Nurse on Ward 7 at the Great North Children’s Hospital in Newcastle, where she helps make hospital as pleasant an experience as possible for the children.

  • Blood tests

    In a blood test, a small sample of your child’s blood will be taken from the body, using a needle. This sample will be looked at by specialists in a laboratory.