Avicenna's Canon of Medicine: a look at health, public health, and environmental sanitation.

Avicenna, a renowned Persian Muslim scientist has written numerous scientific papers and valuable medical books that are respected worldwide. For centuries his masterpiece, the "Canon of Medicine", has been used as a major medical reference. The Canon, as a prime encyclopedia on medicine is comprised of five books. In the introduction to the Canon, Avicenna has described the purpose of medicine as the preservation of health if it is already attained and its restoration when it is lost. He defines health as a trait or state, which results in the normal functioning of the human body and presumes that health is a steady state, whilst disease is more of a variable concept. Thus whenever we depart from a healthy state, we approach disease. A comparison of current views regarding definitions of health, disease and their components as defined by Avicenna could open new horizons for ancient, traditional medicine. The Canon contains numerous implications concerning the infrastructures of public health-related issues. For example the specifications of healthy water and air are well described in the "Canon of Medicine". To enable a better understanding of Avicenna's viewpoints about public health, we have briefly reviewed his perspective on the topics of health, disease, and environmental sanitation concerning water and air.