The blockage of heart arteries is caused by a complex- not completely well understood- process called atherosclerosis. It is characterized by cholesterol deposits in the wall of the arteries that supply blood to the heart muscles. Why do some people have blockage of heart arteries and some do not? It could not just be the cholesterol we eat or manufacture in our body, because we do know that not everyone with high cholesterol has blocked heart arteries and some with perfectly normal cholesterol have heart attacks.
So what exactly causes blocked heart arteries? The simple answer is- we do not know for sure. Several theories have been suggested, however. Could this be due to some infection with a bug? Could this be inflammation? Studies that show that people with high level of C-reactive protein (CRP) are more likely to have heart problems seem to support inflammation theory.