Mitochondria is a central organelle that regulates various physiological functions of the cell, like Reactive oxygen species (ROS) generation, apoptosis, and energy metabolism; its dysfunction due to various stress factors will result in compromised O2 regulation, mitochondrial-related diseases and other conditions. Few studies have shown that Circulating cell-free mitochondrial DNA(CFmt-DNA) content in body fluids will change many stress, environmental and exercise needs. In this study, we aim to understand the relationship between CFmt-DNA and various stress conditions like Alzheimer's disease, Acute Appendicitis, strenuous exercise, major depressive disorder etc.