Why do I have a hematoma in the area where I had my blood taken?

Question

Why do I have a hematoma in the area where I had my blood taken?

Answer 1

Sometimes even if the phleb is good, the blood can leak out so quickly when the needle enters because of the bevel on the needle.  Also they can bleed after the needle is taken out, until the blood clots just like a cut on your finger.  Most of the time it should not be painful unless the phleb had to redirect (dig around). That can also cause a little bruising.  If it is a large hematoma, it can be caused by "blowing" the vein.  Also people who are taking Coumadin (Warfarin) have a tendency to bruise a little more because their blood is so thin.

Answer 2

I like Michele's answer, but even if the vein wasn't blown, blood can leak out of the puncture site into the surrounding area. To prevent this in the future, apply pressure to the site using a cotton ball or 2x2 gauze and keep your arm elevated for 2 - 3 minutes.

Answer 3

Two words:  Inexperienced phlebotomist!

Answer 4

Many people will form a bruise there from blood taken.  If it's especially large and dark (possibly painful), it could be that the needle "blew" your vein, meaning the needle went into your vein and out the other side, causing it to bleed into surrounding tissue.  Either way, it will heal.  And, depending on your healing capabilities (as long as you don't have any problems, like diabetes, immune problems, etc.), it should be gone in about a week!