About 40% of patients undergoing coronary angiography for chest pain with anginal features have angiographically normal or near-normal coronary arteries. It was necessary to standardize all myocardial ischemia scenarios in stable patients in the absence of coronary artery disease, therefore the term INOCA (ischemia with non-obstructive coronary artery disease) was coined. The aim of this article is to summarize and to clarify the vast and controversial chapter of INOCA, in order to better understand the pathophysiological, nosographic, diagnostic and therapeutic aspects.