There's an old saying, "cold hands, warm heart".
Some people just have cold hands, poor circulation or not. I don't think practice could cause it, in fact it probably increases blood flow to your hands. Unless they're painful, numb or change color I wouldn't worry about it healthwise.
As a musician, it could effect you though - cold fingers don't work as well or as fast as warm ones. Get some microwavable hand warmers to use before you play.
Some people just have cold hands, poor circulation or not. I don't think practice could cause it, in fact it probably increases blood flow to your hands. Unless they're painful, numb or change color I wouldn't worry about it healthwise.
As a musician, it could effect you though - cold fingers don't work as well or as fast as warm ones. Get some microwavable hand warmers to use before you play.