Are hematomas common after giving blood?

Sometimes.: I give blood 3-4 times a year and will get a quarter to half dollar sized bruise once a year. Why? Shifting in the needle or a tricky stick can do it. Post procedure elevation and pressure will decrease the possibility. If you are easily bruised on your body, bleeding gums or blood in your urine or stool ... See your doctor. The fact that you can give blood is a good indicator that all is well.