How does a doctor diagnose coronary heart disease?

H&P: History and physical exam (h&p) which includes an ECG (electrocardiogram) and possibly a chest x-ray.

Many things: The first and most important thing in making a diagnosis is listening to the patient. Their signs and symptoms are important. The next is a physical exam. Tests which help include ekg, stress tests, angiogram which visualizes the blockages. Newer tests include ct angiograms, ct calcium score, and mri' s are beginning help as well.