How is coronary artery disease diagnosed?

How is coronary artery disease diagnosed? So most patients are asymptomatic and so they don't have any symptoms and they may have minor furring in arteries not just in the heart but all around the body. In these situations we would not routinely screen or image the coronary arteries just to see if they do or do not have furring because by definition they are asymptomatic and it's not causing a problem. But we absolutely would risk assess individuals just to see what their risk is of both atheroma but also more importantly their risk of a complication associated with it. So if an individual is deemed at high risk on the basis of family history, lifestyle, for example smoking, their cholesterol or blood sugar profile, then we may advocate risk factor modification or primary risk reduction to reduce the risk of a complication associated with coronary artery disease. In patients that present with symptoms, so with chest pain on exertion for for example, or a heart attack or a stroke, then we do perform tests to diagnose coronary disease, for example, a coronary angiogram, where we can inject dye via a small tube, often up the wrist, into the arteries to have a look using x-ray and dye to see if there's a narrowing or a blockage. And sometimes we can also perform non-invasive tests, example a CT scan of the arteries again to see if there is the presence or absence of coronary disease and also how severe and in what distribution that disease is. That's important because that would enable us to optimally manage an individual and guide best therapy.