Causes. Doctors don’t know exactly what causes calciphylaxis, though studies have shown that most of its victims have something wrong with their blood clotting factors. Because of this, these people are subject to small blood clots around their bodies. The way their body metabolizes calcium is also abnormal, and calcium ends up being deposited in their small arteries, or arterioles. This also causes blood clots in these small vessels. Since the skin and other tissue around these blocked arterioles don’t receive enough oxygen and nutrients, they start to necrotize, or die. This leads to ulcers.
