Generally, three major humoral traditions: the Hippocratic-Galenic (or Graeco-Persian-Arab), the Ayuryedic of India, and the Chinese. While the three systems are not entirely identical, they do conform to an equilibrium model where in health, the humors are balanced and when the balance is upset, illness follows. Therapy in each of the three systems seeks to restore the lost humoral balance. The humoral theory is based on the idea that four major fluids dominate the body:blood, phlegm, black bile, and yellow bile. Appropriate foods, drink, and medicines are often used as a means to return the body’s equilibrium when compromised by illness.