Background The importance of microvascular dysfunction in a number of CV disease presentations has been shown by the growing use of invasive and non-invasive coronary and peripheral microvascular evaluation tools. Parallel to this, it has become clear through a deeper knowledge of the molecular processes underlying microvascular dysfunction that the microvascular phenotype is closely controlled by heightened levels of systemic inflammation. The purpose of this research is to identify several factors that may serve as reliable screening tests for microvascular dysfunction. The aim of this study is to determine different clinical, laboratory, echo, and autonomic functions parameters that related to micro-vascular dysfunction as a screening test. Methods: This study was conducted in Beni-Suef university Hospital in the period from October 2020 to June 2022. A total of 152 participants were included in the trial, 76 of them had angina-like chest discomfort, responded well to exercise stress tests, and were shown to have no major stenosis of their coronary arteries on coronary angiography, all while being free of any other particular cardiac illness. Results: In this study, CRP, HDL, LDL, Cholesterol, and triglyceride were higher significantly in cases than controls. Also, the mean latency in upper and lower limb higher significantly in cases than controls. Additionally, there is a significantly higher amplitude of the upper limb in cases than controls. R-R internal variation (RRIV) parameters during rest and during breathing were significantly higher in cases than in controls patients. Results showed that significant roles of latency in lower limb and resting RRIV in prediction of Coronary Micro-Vascular Dysfunction in Patients without Myocardial Disease and Obstructive Atherosclerosis. Results detected that the only autonomic function that found to increase the probability of Coronary Micro-Vascular Dysfunction was the latency in lower limb, presence of Diabetes in addition to the increase of LDL. Conclusion: The well-researched and appropriately standardized established functional tests of the cardiovascular autonomic nerve system are provided here. They often make it possible to evaluate the cardiovascular autonomic nerve system using simple methods. A more precise diagnosis of the risk of micro-vascular dysfunction may be made by frequent testing for autonomic functioning abnormalities.