The extracellular matrix (ECM) is now being intensively studied as a necessary component of living cells. Cells and the ECM are physically connected, via the microtubule assembly, the transmembrane protein integrin, and ECM proteins such as fibronectin, heparin sulfate, and collagen. Not only is the ECM an interconnecting framework, but it also has a direct effect on the cell nucleus. Nutrients must transit through the ECM from capillaries, and wastes must transit through it to lymphatic spaces. Both cellular function and dysfunction-disease processes are intimately bound up with the ECM. In the past 25 years, a staggering amount of knowledge about this aspect of biology has accrued, and for the first time, therapeutic interventions that work via influencing ECM structure and function are becoming possible. Natural medicine has long had modalities that influence the ECM, such as hydrotherapy and herbal medicine, and these are the therapeutic focus of this textbook.