One and a half month ago, I overexercised (went running a lot more than I was used to) and when I finished, my fingernails
were purple/blue. Since then, they have remained purple. A week after that I started developing many other symptoms which I'm quite sure have to do something with that.
I went through several tests including EKG, echocardiogram, xray, spirometry, CT scan and blood work. All came back normal.
My fingernails had never changed their colour before that incident.