This can be due to ischemia -LRB- lack of blood supply -RRB- caused by thrombosis or embolism or due to a hemorrhage .

This can be due to ischemia caused by thrombosis or embolism , or due to a hemorrhage -LRB- PERSON@1 and PERSON@2 's Pathological Basis of Disease , 7th edition -LRB- NUMBER@1 -RRB- , p. NUMBER@2 .
