Why does coronary heart disease cause pain?

Answer 1

Coronary artery disease, in and of itself, does not cause pain. What causes pain is the restriction of blood flow to the cardiac muscle itself, which causes a buildup of metabolic byproducts, including lactic acid and carbon dioxide (amongst others), which results in pain from ischemia and acidosis. The acidosis and ischemia result in abnormal function in the affected muscle, which, depending on where it is, may result in other symptoms, such as shortness of breath, congestive heart failure, and rapid or irregular heart rates.

Coronary artery disease is the process that most frequently leads to the blockage of blood flow, but without the restriction of blood flow, does not cause pain.