Death by natural causes

In medicine, death by natural causes is a loosely-defined term used by coroners describing death when the cause of death was a naturally occurring disease process, or is not apparent given medical history or circumstances. Thus, deaths where the death was caused by active human intervention (as opposed to the failure of medical intervention to prevent death) are excluded from this definition, and are described as unnatural deaths.
The majority of deaths in the US are due to natural causes, and the majority of those deaths occur in old age.
As of the year 2000, the most common natural cause of death in the US is heart disease, accounting for 30% of all deaths. Cancer causes an additional 25% of all US deaths. Other common natural cases are stroke, Alzheimer's Disease, congenital anomalies, genetic disorders (such as cystic fibrosis), serious infections, and respiratory disorders.