In this work, a comprehensive review on Photoplethysmography, its clinical applications and the analysis of PPG signals are given. Photoplethysmography (PPG) is a simple and low-cost optical technique that can be used to detect blood volume changes in the micro vascular layer of tissue. Mostly it is used as a non-invasive technique to make measurements at the skin surface. Five known PPG recordings are studied. Chapter 1 reviews the PPG signals as a marker for clinical applications. Chapter 2 emphasizes the review on PPG analysis with respect to the Heart Rate Turbulence and Ventricular...