Get the latest Natures Gist Health News: breaking health, natural health and medical news around the world, with in-depth features on well-being, food & nutrition, parenting, relationships, diseases and lifestyle. As well known, health is the level of functional and metabolic efficiency of a living organism. In humans it is the ability of individuals or communities to adapt and self-manage when facing physical, mental or social changes. The World Health Organization (WHO) defined health in its broader sense as "a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity. Follow all of Natural and Science Daily's latest research information and top natural/science headlines!