Ischemia
The word "ischemia" () is from Greek ἴσχαιμος "iskhaimos", "staunching blood" from ἴσχω "iskhο", "keep back, restrain" and αἷμα "haima", "blood".
Cerebral edema
During an ischemic stroke, a lack of oxygen and glucose leads to a breakdown of the sodium-calcium pumps on brain cell membranes, which in turn results in a massive buildup of sodium and calcium intracellularly. This causes a rapid uptake of water and subsequent swelling of the cells. It is this swelling of the individual cells of the brain that is seen as the main distinguishing characteristic of cytotoxic edema, as opposed to vasogenic edema, wherein the influx of fluid is typically seen in the interstitial space rather than within the cells themselves. While not all patients who have experienced a stroke will develop a severe edema, those who do have a very poor prognosis.