Had a blood donation on Aug 19th, 2010, one of many times, and it was a very painful experience. The nurse said it would subside in 5 to 10 mins. The next day a large
lump formed
on the back of my elbow and the whole joint area was burning and prickly feeling. This continued for several days, went to see my Dr, and she said it was probably a small collection of blood, that was pressing on the ulnar nerve in my arm. It would dissapate and the pain would go away.