Suggest Treatment For Purpura Caused After Drawing Blood

I just got my blood drawn and the nurse that did it she said that I my veins were kinda closed from not drinking enough, and when she did it the needle came out a little bit and then I started to bleed she called in the dr and she said that there was a pool of blood under the skin! So I m wondering how long does this normally last and is there anything I can do to help it go away faster?