Hello, I am in a phlebotomy program. My right hand was punctured twice this evening. After I arrived home I took off the bandage and saw a large hematoma. For size, picture a dime on it's end tenting under the skin. I applied pressure for 10 minutes and ice off and on over the last 4 hours. I have no pain, only stiffness/soreness. nerve sensation and motor function is intact. Pressure under skin on back of hand keeps me from bending knuckles. It seems serious to me, but when is it serious enough to go to ER?