Determine the topic of the passage. "In medicine , ischemia, also spelled as ischaemia or ischæmia, (; from Greek language ισχαιμία, ischaimía; isch- root denoting a restriction or thinning or to make or grow thin/lean, haema blood ) is a restriction in blood supply to tissues , causing a shortage of oxygen and glucose needed for cellular metabolism (to keep tissue alive)." Topic:

Ischemia