Death and Psycosis

See also: List of causes of death by rate

Death has many potential causes: disease, injury, poisoning, among others. Any of these may damage tissues and organs, and disturb the inner balance that allows vitality (homeostasis). Ultimately, every cause of death in animals does so by breaking the oxygen cycle, cutting off oxygen flow to the brain. All living creatures die, even if they have no particular affliction. Furthermore, every species has its own typical life expectancy. Humans, for example, don't usually pass the 100-year mark, even when they are generally healthy and living in a secure environment. In humans, similar to most mammals, one can discern a slow deterioration in the body's vitality, which eventually results in death.

Current research aims to discover the cause of the body's natural deterioration upon entering old age. Even though findings are generally inconclusive, several theories have been proposed. One theory proposes that the body's deterioration is caused by genetic reasons, as the human genome contains a self-destructive mechanism that kicks off after a specific length of time. Another theory suggests that there is a limit on the rate of cell division which ultimately leads to cell demise (see Telomere).[7] However, many studies show that a proper diet and nutrition together with regular physical activity can extend life expectancy.

In third world countries, inferior sanitary conditions and lack of access to medical technology makes death from infectious diseases more common than in developed countries. One such disease is tuberculosis, a bacterial disease which killed 1.7 million people in 2004.[8]