What Causes Painful And Swollen Index Finger?

for no reason at all last night i had a sharp pain and swelling at the base of my left index finger, it seemed as thou the vein in there was hurt/damaged. it was sore for quite a while. then this morning when i got up the area was purplish/red and tender. not long after i got up the finger started to feel numb and tingly. what do you think the caus eof this could be?