The purpose of this review is to study general behaviour of human systems with respect to the environmental conditions. This type of work will be of profound significance to record the effect of medical treatment in various climatic zones of the world (Arayne and Saify, 1975). We attempted to discuss various facts which would be helpful for tackling the health problems of the people residing in these areas. The statistical data is avoided at the moment and a descriptive pattern is adapted in order to express views, about one of the important aspects of medical science. PMID: 417202 [PubMed – indexed for MEDLINE]