I really run much more than what I was used. When I finished, my
fingernails were purple. Since then, they have stayed that way. A week after that, I started having many other symptoms (headaches, wooziness, etc).
I was told by my doctors that it was raynauds, but now I have found out that raynaud causes attacks and then fingernails come back to normal. Mine are purple all the time, but occasionally my right thumb and left index turn very blue, although they return to purple when I press them.