The elderly, the very young and those with heart or lung disease are particularly at risk of succumbing to influenza and of developing complications. Because influenza may be a serious illness for an individual and an epidemic can cause many deaths and considerable illness with loss of time from work, some form of prevention may [...]

In herbivorous animals, those that eat grass, there is a large extension of the caecum where many bacteria break down and digest the insoluble cellulose which forms the bulk of plants. The appendix may be a left-over organ in the process of evolution. Appendicitis was a rare condition until the end of the 19th Century. [...]