Honestly its better to have thick blood than thin blood!! my blood is like that. Im sure if your worried about it just call the local health department or your doc and ask them. Im sure your fine though.
I knew someone with a rare condition that caused this hypercoagulation. There are other reasons, of course, but I found a site that I found to be interesting, because it also talks about what can be done to treat it.
http://www.yogawiz.com/blog/home-remedies/blood-thickening-polycythemia-symptoms-causes.html