Bruising after a blood test (2014)

Key points below

Why does my child have a bruise?

A bruise is caused by blood pooling under the skin. Sometimes a small bruise will occur when a blood test is done. It may happen at or around the area where the needle was put into your child’s vein. The bruise is temporary and will go away.

Can a bruise be avoided?

Not every bruise can be avoided. Putting pressure on the area where the blood was drawn can help prevent a bruise. Pressure helps stop the flow of blood to the area where the needle was put in. This may keep the blood from pooling under the skin.

What should I do if a bruise happens?

Put a cold pack on the bruised area. This helps prevent swelling and reduce pain. You may purchase a cold pack at a pharmacy or use ice cubes wrapped in a cloth. Put the cold pack on for 10 to 15 minutes and then take it off for one hour. Do this as often as needed for 24 hours.
After using cold packs for the first 24 hours, you may put a warm compress on the bruised area. This helps the bruise heal. It will also reduce pain. The compress should not be hot or steaming; just warm to the touch. Put the warm compress on for 10 to 15 minutes and then take it off for one hour. Do this 4 to 6 times each day for 2 to 3 days.

ALERT

Call your child’s doctor, nurse, or clinic if you have any questions or concerns or if your child has:

Pain or swelling that is very bad or lasts more than 3 days.
A hard time moving the elbow through its normal range of motion.
Bruising that gets worse or feels like a hard lump when touched.
Special health care needs that were not covered by this information.