What is coronary heart disease?

Coronary heart disease is an incredibly common disease.  

It involves the coronary arteries: the arteries which provide oxygenated blood to the heart tissue itself to keep it functioning.  Remember that most arteries run from the heart to other organs in the body; the coronary arteries are the only arteries that supply the heart.  Needless to say, it is important that these arteries function properly.

So, in coronary heart disease there is damage to the coronary arteries.  The most common damage is build up of fatty material on the inside lining of the arteries.  This process is called atherosclerosis - it typically occurs due to a poor diet with fatty foods and excess of smoking.  

So, why is the build up of fatty material a problem? Well, once the material builds up, it starts to decrease the diameter of the vessel.  Think of the fatty material as a mass in a tube: as the mass grows, there is less space in the tube for blood to flow.  This means that less blood flowing through the coronary arteries reaches the heart.  In the long term this can damage the heart and cause it to work less well.

Sometimes, the fatty material can break off from the vessel lining and block the vessel completely.  This can be pretty catastrophic, as no blood will be flowing through the artery and therefore, there can be damage to the heart tissue from lack of blood supply, causing a heart attack (or myocardial infarction).

So, in summary, what is coronary heart disease?

It is a disease involving the build up of fatty material in the coronary arteries.  This can reduce blood supply to the heart.  Coronary heart disease can damage the heart and cause a heart attack.