Death is the permanent cessation of all biological functions that sustain a living organism. Phenomena which commonly bring about death include biological aging (senescence), predation, malnutrition, disease, suicide, murder and accidents or trauma resulting in terminal injury. Bodies of living organisms begin to decompose shortly after death.
In human societies, the nature of death has for millennia been a concern of the world's religious traditions and of philosophical inquiry. This may include a belief in some kind of resurrection (associated with Abrahamic religions), reincarnation (associated with Dharmic religions), or that consciousness permanently ceases to exist, known as oblivion (associated sometimes with atheism).
The response after death includes various feelings of grief or emotional suffering one feels when someone the individual loves has died. Commemoration ceremonies after death may include various mourning or funereal practices. The physical remains of a person, commonly known as a corpse or body, are usually interred whole or cremated, though among the world's cultures there are a variety of other methods of mortuary disposal. In the English language, blessings directed towards a deceased person include rest in peace, or its initials RIP.
The most common cause of human deaths in the world is heart disease, followed by stroke and other cerebrovascular diseases, and on the third place lower respiratory infections
The word death comes from Old English deað, which in turn comes from Proto-Germanic *dauþaz (reconstructed by etymological analysis). This comes from the Proto-Indo-European stem *dheu- meaning the "Process, act, condition of dying".