User blog comment:Xilinoc/Ch. 568. Hear. Fear. Here 2/@comment-6299840-20140212100929/@comment-4666155-20140212101853

Life and death in BLEACH are pretty much two sides of the same coin; a Shinigami's body has the same bodily functions as a human; they eat, sleep, breathe, bleed, everything we do. A soul is pretty much the same as a human body, only it's made of reishi as opposed to kishi (I believe that's the term used for physical matter). So, while they are "dead", it's not too different from being "alive"