No offence, but I will rule out a lung squeeze. I would like to think that if I did have one I would know it.
I have done my fair share of exhale dives (25m) without a squeeze of lungs, but thanks for the idea.
This blood is either coming from my throat area or sinus. Either way it is my fault for overtraining them. So now I go back to the basics. Sailing my boat as often as possible and a little less gym training to let the body heal.
Just as the terminator once said, " I'll Be Back!"
So will I.
J