Electron Paramagnetic Resonance (EPR) spectroscopy - also sometimes termed Electron Spin Resonance spectroscopy - has manifold potential uses in biochemistry and medicine. The paramount importance of EPR spectroscopy applied to biological tissues and fluids is that it identifies the changes in redox processes that contribute to disease. EPR spectroscopy has come a long way from its original use to detect malignant tumors. For example, the development and later refinement of methods of low-temperature registration of biological tissues widened the scope of EPR spectroscopy. Innovations made possible by the introduction of spin labels, probes, and traps made EPR spectroscopy ever more applicable to biochemistry and medicine, to the point where in vivo studies are being carefully considered. This comprehensive book discusses spectra of many tissues and bodily fluids, and the quantitative nature of paramagnetic centers in both normal individuals and patients suffering from a variety of diseases. Special attention is given to the EPR examination of bio-molecules, such as enzymes, polypeptides, vitamins, lipids, hydrocarbons, etc., which play an essential role in human activity. This book will be of great interest to physicians specializing in many different areas. Similarly, biologists, biochemists, biophysicists, and chemists will find this book very useful. It has also been written so that it may be used as a textbook at graduate level.