Ans. If the blood circulation is stopped or reduced, then necrosis is caused. This can be happened because of- More deposits of cholesterol and fatty acids in the bones. It causes the stuck in blood to flow from one organ to another.Joint damages and Bone damages are also other causes of necrosis. Some drama or accident happened, and damage has taken place at the joints and the bones.Several diseases which are already there in the human body which leads to the interruption of blood flow will become another cause for necrosis.