Why is it important to be careful with cholesterol? Does it cause heart attacks?

Yes, cholesterol contributes to the risk of heart attacks. When it combines with fat and calcium, it forms plaque. Plaque can build up on the walls of arteries, choking off blood flow in a condition called arteriosclerosis. The plaque can break off in chunks, which form blood clots, or it can start to put pressure on the heart itself. Over time, this can lead to a heart attack or ‘myocardial infarction.’

In myocardial infarction, one of the coronary arteries gets blocked (usually by plaque) and the lack of blood supply starts killing off muscle cells in the heart. This is a painful condition and weakens the heart through cell death (necrosis). In severe cases, it can be fatal, and this is the main cause of death for adults in the developed world.