Heart disease is an umbrella term for a variety of diseases that can affect the heart with a variety of possible outcomes. Heart disease is also the leading cause of death in the United States, Canada, England and Wales. It accounts for a full quarter of all fatalities in the United States. This terrible track record is one of the biggest reasons why high cholesterol levels are such a consistent concern. Cholesterol levels are one of the most controllable factors that increase the risk of heart disease. That being said, it can often help to understand exactly how heart disease works.

Coronary heart disease is one of the most common types of heart disease. It specifically refers to failure of the coronary heart circulation. Coronary heart arteries supply oxygenated blood to the cardiac muscle and surrounding tissues. Coronary heart disease is most commonly equated with coronary artery disease, which is usually a direct result of high cholesterol. However, coronary heart disease may also be due to other causes, such as coronary vasospasm or other muscular deficiencies. Whatever the underlying reason, coronary heart disease deprives the heart muscle of the oxygenated blood that it requires to work properly. As such, it is one of the most common varieties of heart disease.

Cardiomyopathy is another form of heart disease in which the heart muscle itself has degenerated. This cardiac degeneration can occur for a number of different reasons, cholesterol related atherosclerosis being one of them. Other causes of cardiomyopathy include chronic alcoholism, chronic high blood pressure, or congenital defects such as inborn weakness within the heart muscle itself.

The rarest form of heart disease is severe congenital heart defects that actually deform the heart structure. These sorts of congenital heart defects often start affecting newborn children as soon as they have to rely on their own circulation instead of getting all their circulation from Mom. They can frequently be fixed by surgery if they are caught in time, but are often fatal when testing or surgery can't be done. Screening for congenital heart defects has become more and more sophisticated, allowing high risk children to be diagnosed before birth. However, these sorts of heart defects are also the least preventable form of heart disease.

The heart is a very complicated part of the body and there's obviously a lot that can go wrong with it. Some things are within our conscious control, such as our lifestyle choices. Other factors are not within our ability to control, such as the genetic likelihood of heart disease or genetically determined high cholesterol levels. Surgeries such as angioplasty and bypass surgery have also increased the recovery rate for heart disease. It's still a major problem throughout the post-industrial world, reducing both quality and length of life for uncounted people, and as such should be taken quite seriously.